Just received the email invite to beta-own one and the selection process is handled well - a web interface that lets you preview and select which sim and which house-style you would like.

Unfortunately the houses themselves are all pretty awful and of no interest to me, even as a curious beta-tester so I logged out again. I applaud the initiative, I've thought SL needed something like this for a long time, but when the houses themselves are a bit awful and un-modifiable it's slightly disappointing.