old french bike to fixed
 

So i have an old french bike. I heard that they might not be so great for a fixie because of the relaxed frame? Also, what are my alternatives to getting a new bottom bracket and headset on teh cheap? Looks like the headset can be done with ISO parts since more than likely the lower races are the things that are shot. Can someone confirm this?
Also, as far as the bb is concerned. It is a cottered crank. I intend on putting a square taped crank in place but after shopping around it looks like the conversion is going to be expensive. Would I be able to keep the cups and get a new axel/bearings? Or is it more involved than this?

Thanks!

bluenote157, you've come to the right place. all your questions and more are answered, click here and read. Just one update, the Sugino BB cups are available again at Sheldon Brown's website, so you can use a "regular" length spindle.
You're gonna have so much fun!

you can get stronglight headsets that are french threaded. they have tapered roller bearings and are really nice and fairly inexpensive.

as far as your bottom bracket, you could easily keep the original cups and replace the spindle. i did the same thing on my peugeot.

good luck. french bikes are sometimes a pain, but fully worth it.