I'm just finishing up a kitchen re-do (my 5th). I've been through all the issues you're raising including moving walls (including bearing walls), changing fuels, relocating everything, cabinet design, finish selection etc. Let me take your last question first. I have experience with travertine - recently installed some in a downstairs hall area (about 200 sq. feet). It's beautiful material, but I strongly suggest you avoid this choice for a kitchen. Travertine is at once too hard and too soft. What I mean is it is too hard for comfort as a work-area floor and too soft in terms of porosity. Hard - uncomfortable. Hard - anything you drop will break. Soft - anything you drop and break will stain the floor (red wine, vinegar, etc.). Kitchen floors should be easy on your feet and back and easy to keep looking good. I would also suggest avoiding the travertine-like tile. It may avoid the porosity problem, but it will still be hard to live with. By far the best material with a visual texture along the lines of travertine would be cork. As an added bonus it can be found in many textures and colors. Now as to the suggestion of moving the stove/sink and combining the kitchen and living spaces. The things you want to be thinking about at this point are mechanical issues that may not have occurred to you. You'll want very good ventilation to remove both odors and grease and you'll want it to be quiet enough so your living area is not impacted too much when cooking. As for the sink, if you're proposing to place it along the LR party wall (with new pass-through/counter/snack bar), you'll have to think through venting the sink. You say the dw is on that wall now, but that appliance is not vented - it shares the plumbing with your existing sink. You should definitely consult a plumber before you start on this. Venting can be a pain. It (the ease/cost) will all depend on where things already are in your walls and floors. Corian - A nice (if overly expensive) material, but be aware that you can't put hot things down on it directly. Finally, if I understood you correctly you're talking about removing or revising two walls. One or more may be bearing. If that's the case, you'll need to figure out how you're going to pick up the load. In my most recent kitchen re-do I removed two walls and needed engineered steel in both. -RetroDiner