You need to do a little more archeological digging still. You need to know the whole construction of the floor before you can decide how best to install something new. I'd take up that plywood piece in the kitchen and see what's under it. It's higher than the surrounding floor, so needs to go. You should also be able to see from there what subfloor is under the original kitchen hardwood. It's too bad the space under your entryway is finished, but I'd still do some exploring from below to see what's under there, and to figure out the fix to stop it from squeaking. Is it drywall below or a drop ceiling? I know it probably seems like a pain to tear out drywall, but if you cut out a clean patch, like 2' x the width of the joists, it'll be relatively simple to repair. Just make sure to cut it down the center of the joists so that there's room to screw the patch piece to it later. Cut the hole under the area that squeaks the most, if you can. Have someone walk on and watch the floor from below to see what's moving. It might be as simple as pounding in a couple shims from below, or face-nailing a loose board from above. You want to find out what's underneath the hardwood. It might be laid directly on the floor joists, or there might be 10" wide boards that the hardwood is nailed to. Another thought is to take out a board in the hallway, since that's not original and you want to replace it. See what the subfloor is there. I am a bit puzzled at why, when you've stripped the kitchen down to the original hardwood, it's still higher than the hallway floor. Is your current surface perhaps not the original kitchen hardwood? Peeling back the plywood area will help determine that. BTW, I haven't heard of that stop squeaking product you linked to, so can't offer any personal opinion. And don't pour self-leveling compound over top of hardwood. It needs to go over plywood.

As ever, the answer will be found in your choice of product and the value of your home. And location. And install....and...and...and...Sigh. You get the point. In an area where engineered hardwood is the NORM (Mississippi flood plain), then it would be unusual to see solid hardwood (and if you know anything about flooring it would be a MASSIVE worry for the next home owner). If you are in an area where solid hard woods are de rigueur then engineered hardwoods *might pose a concern...but might not. The actual value of your home is something to consider as well. For instance a $1.4M home in NE USA would be a place you would EXPECT to see solid hardwood (and something stunningly beautiful at that!). A $3.99/sf Home Depot product installed into a mansion in Boston would be a poor investment choice. The revers is also true. A $200K home in the middle of nowhere would not benefit from a $15/sf solid European Oak hardwood. The amount of money put into the floors would never be recovered with resale.

hardwod floors are always and will always be the look. though people seem to not underatand thatbthe reason why these products exist outside of harwood. hardwood is just not practical anymore , yesrs ago youd have certain rooms with different flooring to accommodate the room , now, its all usually open concept and having patchy flooring all over doesnt work. honestly i just dont see hoe you can put hardwood lets say in a kitchen , kitchens take a beating , if you can afford to or want to samf your floors every few years , espec especially if you have a busy household , them go for it , i know of no one that has ever resanded their floors and if so , what a mess. so lvp , laminate etc… all have come along due to the demand for the wood look without the issues of hardwood , so its all a decsion though we have decided on 1400sq ft of coretec lvp, we just love the hardwood though just not practical anymore , i cant have adults and kids tip toeing on our floors. plus in the future if you want a new floor , just pick it up , no demo. just my opinion

Leather is the most 'recognizable' pattern for cork (other than the ground up cork board look). When it is laid it looks like hardwood flooring using 'shorts'. It has a bit of a brick look to it. Ignore the 'pink' in the samples. The pink is the very first colour to fade away. It takes a few months for the pink to disappear but once it is gone the cork (Leather and Logan) will look more like oak in tone (yellowish with some hints of green and some gray). It is a 'directional pattern' which means it has a 'linear' sense to it. The Logan is the most expensive cork pattern you can get. The slices of pattern are random. They are hand cut and hand laid. It takes *roughly an hour for 1 person to arrange 10sf of the pattern. It is STUNNING. It looks more like stone. It is random...did I mention the pattern is random? Leather and Logan can have the extra 2 coats of the Loba 2K Supra AT = super tough. The Latte is a FANTASTICLY tough finish. It has the polypropylene finish on it. This is the 'non-vinyl' product Cancork sells. It is tough....right after that it is SUPER TOUGH. And then for good measure, it is TOUGH!!! For a Rental property, the Latte is a product I would recommend. It does NOT need the Loba product. That means you save $1.50/sf RIGHT AWAY. It can handle 3mm or 6mm cork underlay. If you are looking for temperature control, then I like the 6mm underneath...but CHECK your door heights, etc. All you need to do is take your floor sample and the underlay sample they sent you (their supposed to do that...sigh) and see if it 'slips' underneath the doors in your home. It is that simple. I hope that helps... As for the Tacoma...I'm guessing you are looking at KILOGRAMS (700 kg) as your weight limit = 1540 lbs. The weight of a standard skid of cork flooring = 1000sf (ish...depends on the product) = *roughly 2000 lbs. And the skid sizes are PERFECT to fit between the wheel wells of a truck bed. I've watched this stuff get loaded into pick-up trucks for 6+ years. A forklift operator can drop that baby into your truck (so long as you do NOT have a 'cap-it') and off you go. If you only have a short way to go, the 2000 lbs won't be much of a problem...I just wouldn't do a trip to Bella Coola with it. ;-)