Geckos are widely regarded as the best stepper drives available in their class, although the likes of the Chinese Leadshine ones are close. Geckos servo drives however are way behind others from most reports.
Regarding a BOB, then I would say PMDX are the best, but that is just my opinion
Another thing to think about is a motion controller, you may wish to simply use the parallel port or you may have to go with a moton controller. If going with a controller then there are quite a few out there in varying price ranges, the Ethernet SmoothStepper is a decent choice but you will need at least one BOB for using with it (well not needed but best IMO) another choice would be the CSMIO/IP-M, that would not require a BOB as it has basically got it all built in. Lots of choices there and there will be lots of varying opinions
Hood