See SheldonBrown.com for some great tips on French bikes. Changing the fork will permit you to use ISO/standard diameter and thread stem and headset and will probably result in quicker, more nimble steering than the long-raked original. However, check it out for toe-to-tire overlap (my UO-8, with an aftermarket short-rake fork, has a bit of this), and make sure you are comfortable with this (I am; the CPSC is not).
__________________
"Far and away the best prize that life offers is the chance to work hard at work worth doing." --Theodore Roosevelt
Capo: 1959 Modell Campagnolo, S/N 40324; 1960 Sieger (2), S/N 42624, 42597
Carlton: 1962 Franco Suisse, S/N K7911
Peugeot: 1970 UO-8, S/N 0010468
Bianchi: 1982 Campione d'Italia, S/N 1.M9914
Schwinn: 1988 Project KOM-10, S/N F804069