Originally Posted by mattface

sure, upgrade the fork, headset, stem, bars, then do the frame, seatpost, bottom bracket cranks, and wheelset.

In other words, unless you want a whole new bike, don't bother upgrading the fork, before you know it you'll have piecemealed it into a whole different bike. Better to find the frame and fork you want, and select your parts around that.

Originally Posted by DiegoFrogs

I highly doubt you have some proprietary fork. Why would you assume that it is so? Lesser models like the varsity did have some proprietary sizings, but your letour is probably made in Japan by Panasonic.

Other than the probably JIS headset race, I wouldn't expect anything out of the ordinary. There are JIS threaded headsets available today, too.