Originally Posted by sivat
The only problem with french (peugot) bikes are that replacement bottom brackets can be expensive.
My circa 1979/1980 Peugeot takes a plain old 68mm BB. I found a drivetrain (BB, chainring, crankset) on eBay for $60 and it popped right in.
Both of those bikes you linked to are too small for you. That aside, I recently converted my 10 speed Peugeot into a fixed and it cost the following, for reference purposes:
Mavic CXP22 wheelset with Formula Sealed Bearing Hubs Silver ( Fixed-Free ) = $135
drivetrain = $60
DuraAce track cog = $15
DuraAce lockring = $8
WSD saddle = $35
2 Avocet tires and 2 presta valve tubes = $60
purple BMX chain = $12
So that's about $300 just in parts. If you don't have tools or any of the other misc. crap you need to do all this stuff, you're looking at another chunk of change.