Bicycle Mechanics - Upgrading an old peugeot.

I recently bought a peugeot pgn10 and Im trying to turn it into a fixie. The problem is every part I thought I could keep is worn out (crankset, bb, headset) I was wondering if anyone knows what my options are.
Im thinking this bb
http://www.velo-orange.com/grcruthbobr.html

this crank
http://www.velo-orange.com/suxdtrcrhipo.html

But I really have a question about the headset. Am I stuck with the french threading, or could I change the fork and headset to a modern threadless?

Well, since this came up on another thread that is still currently running the first question you need to ask yourself is if the frame itself is worthy of spending this sort of money on it. I only ask because Peugots came in a wide variety of quality levels. A quick google turns up that it was made from Reynolds 501 and seems to be a mid level bike of its day. My first thought at seeing that is that it may be worth fixing up but not if the cost seems up there for your tastes. And that cost is climbing since you're talking about the cranks and BB along with a possible new fork and headset.

When you add up those things and look around you may find that you can pick up another old bike where all these parts are good for less money. And check Ebay for track cranksets. I'm sure I've seen them there for cheaper.

Of course if you like the looks of the frame and that love affair is making you want to stick with it then carry on. Not all of this stuff needs to follow logic. Especially when something French is the topic.... :D

I want to thank you for the link to the threadless BB. I've got a sweet riding older Canondale that recently stripped the threading out of the BB shell. That threadless BB is just the ticket for the needed repair.