Alan Photo has a good stock of flim scanners. Prices, as members here can testify is one of the best.
CP also has some and when I was shopping for my scanner, I looked at a few Minolta scanners there.
I advice you to get some feedback from members about the model you are looking for. Resolution is not the most important thing. Some scanners advertise a maximum resolution of 4000dpi but you will hardly use it because it takes a damn long time to scan.
So other than dpi, you have to consider speed and ease of loading.