I've been looking at Sheldon Brown's site and reading up about building my Motobecane Mixte into a single speed, and I have a couple of questions.

1. I noticed in the fixed gear/single speed galleries that a lot of times they just use a front brake. Is this a good idea as I'm going to use this as an errand bike around town?

2. It seems that 27" wheels are easier to align than 700c, but either size will work. (The wheels on it now are 27". I think this bike is from the 70s) Correct? I want wheels with the flip flop hubs, and there are several of both kinds on ebay. Anyone have any recommendations?

Thanks in advance!