flat 7 mile commute. Do it! I'm all about a fun project. I've built up a couple of SS/Fixed gears through spare parts and craigslist finds.
Btw.. in case you didn't know, you can take an older freewheel wheel and thread on a bmx freewheel. You might have to redish your wheel.
Or.. you can get a freehub body and buy a SS conversion kit.
I have a brand new SS conversion kit I'm trying to get rid of. It comes with spacers, lockring, 16t, and 18t cog. PM me if interested.