Steve, Beutiful floor and room. Unevenness in the substrate causes the majority of lippage issues. What I am referring to is the tile itself is coming out of the box slightly concave (I think the standards refer to this as allowable warpage) and it is causing issues in installation. We just had a recent case in a contemporary tile that was a 6" x 24" which was to be installed on the walls in a running bond pattern. The tile setter started the shower but we couldn't stand the lippage so met with the customers and ended up cutting the tile down in size to minimize the impact. The tiles were cupped enough that the result was visible. These were nice tiles that met the industry standards, we just couldn't live with how visible it was, particularly in certain light. If there are some master tile setters out there that can address how you deal with this, when the substate is properly prepared, we would love to know. Given the design trends, this is becoming more of an issue. Maybe I will post this in Pro to Pro as well.

I like American Olean's Decorum series, color DRO1, in the 12 x 24" size. The DRO1 color is called "Ideal White", which is actually a cream color but it looks great with the white marble countertop in our guest bath. It comes polished and matte finish. I'd use the matte finish on the floor. For the walls you can choose either the polished or the matte finish.

Can you post pics of the kitchen too?

I would consult with your builder as to a landscape/hardscape source. You want pavers of some sort, not an interior tile. A covered "patio" is not a sunroom, nor is a covered porch. You want outdoor materials. Maybe a bluestone., or slate which comes in a host of tones, from blues to greens to black. You'll achieve a far more natural look as well.