Hi there, I don't think the hearth will effect the mantle/TV height at all. I assume you'll be doing a mantle above the firebox? I personally would do a hearth with a two story fireplace to maintain the balance. It's also nice to sit on the hearth!!! Take a look online for photos and see what your think. Houzz and Pinterest have some great fireplace photos. Our hearth in our remodel was a stone fireplace with a 1' hearth topped with slate. It had a regular height mantle...and a TV would've looked just fine above it.

Excuse me for thinking your sunporch was another bathroom. The drawing is not that clear, and it appeared to contain hand drawn bath fixtures. Google Sketchup is a free program that you can use to make your drawings clearer to you and to others. There are also several low cost programs that work well for layouts including a homeowner version of Chief Architect. If your whole roof will need to be replaced, it's a good opportunity to work with an architect or at least some software to rearrange much of your space for better flow. Maybe add some dormers upstairs to get more light into the space there? Approximately 60% of your space is devoted to storage, hallways, and other non public areas that do not add anything to your living space. I never said that you don't need those spaces, just that they are too large given the size of the rest of the home and they duplicate functions. This makes them an unwise use of precious HVAC. Especially in a cold climate. You're spending a lot of money to heat and cool those spaces. You can achieve much better use of your square footage by combining some of those areas and elminating the many dead areas that exist. BTW, I'm not holligator. I've been on GW since 1994 when Spike ran the joint and regularly sent folks whose posts he didn't like to Disney. Literally. I was a regular and respected contributor to the Rose Forums for many many years before my job got in the way. BTW, that job involves being paid to space plan, to work with traffic flow patterns, and to use ergonomic studies and industrial psychology to make a home environment functional, comfortable, and decorative. I've never had anyone object to getting free advice from a professional before. I stand by what I said. You have some good ideas as a jumping off point, but you badly need an in person professional to help you realize those ideas more efficiently. Renovation is extremely expensive, and there's nothing more frustrating than to regret how you spent those precious dollars. As one of my old professors said, bad design is obvious. Good design is invisible. You never notice when things are placed correctly. Just when they aren't. Please consult a professional for help. It will be the best money you'll ever spend on the project.

I can see the appeal, terriks, but I think the Platinum, while a lovely color, is too blue for your scheme. Rather than the color picking up the tones in the tile, I think it's putting the colors into the tile - both your shades are reflected in it in your photo - and I think a slightly warmer companion to the red would give you a more natural effect. Revere Pewter would be worth a look, and if it's still too taupe for you (it's paler and less brown than Rockport), take a look at Balboa Mist (also B. Moore), which is clearly gray, but warmer than Platinum. I think with the reflected colors in the tile, the warmer gray will be much prettier and more like mother-of-pearl, which is what I see in your tile.

I love the new tiles also. If you want to DIY for the slate, make a paper template for the hearth and then transfer this to a thin wood or a sturdy cardboard. You can then take the fitted wood or cardboard template to a stone yard to have the stone cut to fit. If you hire a professional, they can remove the white tiles before installing stone.