Yeah most people use more than one synth, in my case I never was able to dish out the 3K+ for a workstation in one shot.

I know many people suggest going with the XV88, it looks like a really nice board but not sure if its going to do everything you are looking for. You may want to look at either the Kurz K2600 or the Korg Triton. In either case both machines have a sequencer built in and if you dont like the drum tones they also support sampling. You could sample the drum tones that you want and do a great deal of your work on that one board.

The Kurz are now on a limited lower price sale which have them priced a little more than the Triton. But you have to pay extra to add samplimg on the Kurz. I know there are 3rd party vendors that have Hard Disk adpators for the Triton so you could add an internal HD if you wanted.

You may want to get over to the local music store and compare the Roland/Korg/Kurz workstations.

On a side note Yamaha is coming out with their own workstation called the Motif I dont know when that one is coming out.