Looking for the right parts...
 

Wanting to take an old steel frame and convert to single speed for my regular commute. Flat, 8 miles one way through Houston. I dont know anything about the bikes, but my current options are:
1980 Schwinn Super Le Tour
1976 Motobecane Super Mirage
~1970's Mirage 710

Thoughts on the frames? All appear to be in pretty good shape. Leaning toward the Motobecane as its prettiest. Ha.

Also, info on what additional parts I'll need to buy for the conversion would be awesome. I was just planning on picking it all up off Nashbar or something, since I figured that would be most affordable. Thanks!
dan

Any will do fine, though the Mirage's may be french threaded, which adds an interesting wrinkle as far as parts availability. If you want to mailorder the parts easily, go for the schwinn.

www.irocycle.com is a great source for bike parts, and at the very least sells better wheels for a similar price to the nashbar ones. You might also try your LBS, I'll bet they have an old parts bin that would work well for some stuff.