GDB,
I would save a bit longer and get the XP-30, because it would be easier to change sounds while playing a gig. I am sure the JV-1010 is a fine piece for what it does, but I tend to think it is more geared towards computer interaction, because of the lack of display and buttons.
I am sure you could use the program changes, but if you are like me, you like to have things easily accessible. I am more of a hands-on type of guy, and prefer to have multiple keyboards in front of me, instead of just one controlling everything. I think that particular setup is best for the studio, because you may not need to access parameters or sounds as quickly.
Plus, the XP-30 has the built in expansion cards and more available expansion slots. If you are looking for a good module, I have heard that the SC-880 is a fine piece that might do the trick for you. I think they are discontinued now, so you should be able to find them fairly cheap.
I hope this helps you.
DanO