Diameters won't be the problem, only finding the metric threaded headset for the steerer threads. As we discussed before, you can avoid that by making the switch to the threadless (really threadless, without adapter) now instead of later. Make no mistake, I understand the economic issues you mentioned, just sayin' finding the French headset and the cost of it may make doing the change now the right thing. There are some good buys on fairly light, carbon, threadless forks for 1" if you look hard enough. I think Wiggle had one. I'm talking $100-200, not $400. Good luck.

EDIT: Here is one you can order (and Wiggle has to order it too). Not as light as cheap as I thought, but not too bad: http://www.wiggle.com/columbus-minimal-road-forks/

If you don't mind a bit heavy with Al steerer, Nashbar has them all the time for just a little over $100.