I am also building a new house and would like to put together something as a project over next winter. I think what would interest me the most is one of two things (depending on if I have any "extra" computers when I start);
1. The stuff typically required to convert my average ~2 year old desktop computer to a linuxmce capable machine (capture card, remote, specific video cards...) or
2. Kind of a barebones DIY kit with a cost efficient and reliable processor, motherboard, capture card, remote, etc (minus hard disk and case, people may want various sizes/colors etc, maybe they could find what they'd like from another area in your store!). This kit would be marginally above the "minimum" requirements so it functions reliably, but doesn't have to be able to do everything at once. I can build it and install the software I just don't want to spend hours and hours researching and testing/failing different models of products. If you assure me that I can open the box, put it together, and install and be ready to go that afternoon, I'd pay a premium.