I'm a newbie to kitchens but even I can see that the location of your cooktop is a significant safety hazard. Like meganmca mentioned, you've got what looks like cabinets butted up on either side. Combustible materials need to have a certain amount of clearance away from the cooktop.

The other issue with having those walls tight up against the cooktop is that you don't have any landing areas nearby to set down hot or heavy pots or pans. That could be very hazardous.

Wow! Did you put that cooktop there or did you "inherit" it? Don't answer that. Just know that it's a very poor and dangerous setup and, if you change to a range, you may be required to bring it up to Code - that means, at the very least, providing proper clearances around the range per the range's manufacturer's specifications. In some localities, you may have even stricter requirements.

From a functional point of view - you have no landing space around that cooktop - not even enough for "emergency landing space"!

Something else to keep in mind is that a range sometimes takes up more room than a cooktop - so you may not have enough room to fit a range in that space - even if you ignore the safety requirements.

With that said.......

Will you be taking the "non functional oven" out as well? If so, if you also remove the entire oven cabinet, then you will probably have enough room to do what you plan in that full space (existing cooktop + existing oven cabinet space) and have enough room to meet Code and provide emergency landing space. probably not enough for truly functional landing/work space, but enough in case of an emergency - e.g., a pan on fire.

Heat proof - possibly some fire resistant wall covering? I don't know what's out there, maybe someone else does? It will probably be something industrial.

What about covering the walls with stainless steel and having a stainless steel hood above? That'll be a lot of stainless steel, but I think that would fireproof it - I'd check with some pros about that.

I assume (hope) you have a hood above the cooktop? If not, I strongly recommend getting one when you replace the cooktop.

Here's a suggestion:

If you remove both the cooktop cabinets and the wall oven cabinet, you could then put in cabinets on either side of the range. You'll at least regain what you lose in the bottom of the oven cabinet - and probably more b/c I suspect the oven is partly below the counter. E.g., if you have a 33" wide oven cabinet + a 30" cooktop cabinet, that leaves you with 63" to work with:

Assume around 30.5" needed for a 30" range - including the required clearances around it.

So 63" = 30.5" = 32.5"

I'd put a 15" pullout on one side and a 17.5" one on the other side. If you can steal some space from one of the sides, I'd try for 18" on the wider side. If not, then I would at least get a 17" cabinet.

You sound like a DIYer...so maybe get IKEA cabinets and then hack them to fit in your space.

Note that if that "wall" I see on the left is an actual wall and not another cabinet, you may also need approx 1/2" of filler b/w the wall and the cabinet on that side.

Off the topic a bit but have you considered an induction range instead? The area still looks unsafe as is but at least you won't have open flame to deal with. Many people who go from gas ranges to induction are very happy with them.

I have to agree that the current situation is dangerous. However, once the oven is gone, presumably there would be appropriate clearances for safety that would be listed on a new stove. If you got a used unit then some serious reading would be needed. The induction idea is worth consideration.

Back to your initial question: I may disagree with maganmca and lily'smom. It depends on your experience and tools. Yes, gas can be dangerous. Do you already have some plumbing experience? Have you replaced or extended a galvanized water line? Have you reattached some toilet or faucet lines and noted that you can cause leaks with over as well as under tightening? If not, the plumber is in order. In your specific case, it seems likely that all your fittings including the flex line are already there. If the pipe diameters of the current cook top and new stove were the same size you just transfer the flex line to the stove; use teflon tape for any connections. Regular stoves have room for the pipes in the position that you show.

Wow! Thanks to all the responders! So, to clarify some things, I very much inherited the current situation. There is a vent hood and on the cabinets on either side of the cooktop, there are metal sheets attached protecting that wood. My assumption is that I would need to install that all the way down after removing the cabinet.

The non-functional oven is likely from the seventies and built into the cabinet. I can't afford a replacement double oven that would fit there, which led to this freestanding oven idea. On the other side is a floor to ceiling pantry that I'd like to keep, but I'm not married to anything.

I do have experience with plumbing, just not with gas. I had to call a plumber out to get this to code already, so I was hoping to just modify their work, but I don't need to take unnecessary chances of it really is that dangerous. Really just wanted that clarification on whether that piping could be left intact and still fit behind.

Thanks again, open to any more advice out there!

Good that you have some plumbing experience. However, I just realized that I hadn't thought through your situation quite right although I did suspect that you might already have metal sides. Normally, the gas line comes in much nearer to the floor and I was kind of thinking that was where it is. I haven't really looked at stoves lately, but I suspect that they don't give you room in the back near the top, but only near the bottom. If you didn't reroute the gas line to come into the house nearer the floor, the stove would probably need to sit slightly away from the wall. Doing the rerouting is real plumbing, and in fact, you would already need to turn off the gas at the meter because you will likely (although not absolutely necessarily) need to remove and cap off the current oven line. And then relight all gas appliances if they are old with pilots. And that flex line would probably be too short to install a stove rather than the cooktop because a stove has to be slid all the way out (and extra out in your probably still constrained case) to get behind and attach the line.