Please stcked stone is already dated and IMO never really belonged indoors at all If you really want help we need info . What is your style maybe some pics of your interiors where you are , IMO the srched window will drive the rest of the design of the FP.

I would clean and paint the one you have. It will be gorgeous, once its cleaned. The other one is very modern, and appears to be an electric type fireplace, or possibly gas. Yours looks to be wood burning, and it also fits your house (what I can see of it), more than your inspriration pictures.

Very cool mock up and walk through! It looks like it’ll be a space you will enjoy. If I were to be rather picky, I’d say the bar stools by the back tv area seems a bit crowded… but it could just be the picture/ software. In the mock up it shows a back splash on the posts… I’d probably remove that. And if were my space, I’d move the stove top to the wall instead of in the Island and hang some nice lights there instead of a vent hanging down. What an exciting space!

Corner fireplaces are always huge problems for a furniture placement space plan. Just remove it. There’s a lot of combustible material in that pic that is likely way too close to the heat source if you do keep it. Dig out the manufacturer’s requirements for distance to combustible materials. That wood framing may need to be metal, and all of that tacky beadboard wainscotting for sure needs to disappear, even if its a zero clearance unit. The cheapest facing would be drywall, with a faux plaster finish. But, if you are going to do stone, or other cladding that has significant depth, that has to be factored into the framing surrounding it, when you reframe it. You cannot frame it for thin drywall, and then put on 3” of stone facing. All of the math on the depths has to work, and you have to design for the size and depth cladding material you want when you reframe it.