I'm currently using the UCN5804B

Can cope with up to 1.5A per coil
Unipolar motors
Half or full step mode
Step trigger pin
Direction pin

See:

http://www.alltronics.com/download/5804.pdf

I'm controlling this via a computer, via a PIC, and sing a couple of stepper motors from active robots (UK online shop)

http://www.active-robots.com/product.../stepper.shtml

They seem to work very well...
The IC has all the drive circuits and sequences internal, so nothing else needed (except a few caps)

Cheers,


Ben