I changed a canti fork to a non canti using a centerpull brake keeping the canti in back and rode the bike that way for years as a year 'round commuter. No issues at all. I now run Mafac Racer centerpulls as fronts on my two winter/rain/city bikes with Weinmann centerpull rears. (I took a set of each and turned the rear Mafac into a front and vixce versa for the Weinmann.) I like the more powerful brakes in front and the stiffer brakes in the rear. With the spongier feel from the longer rear cable and housing, they feel more alike.

As others have said there is no magic to brakes. They don't have to match. You do want front brakes you trust. In a pinch, that is the brake that's going to save your butt. But there are lots of good ones of all types.

Another option - this will cost you a few bucks but you get exactly what you want. Have a fork made for you. The builder can braze on canti bosses, match the old fork's dimensions and headset dimensions and not force you to mess with a new stem. Want fender eyes of Lowrider bosses? Now's the time. A really cool fork crown? My Mooney is riding its second fork. Nicer than the first.

Ben