Tomorrow:
Frankly, in my humble opinion, getting another piece of software to do what Cakewalk itself will do just fine is kinda silly. If you'll look in your JV-1010 manual, page 33 (page 37 for rhythmn), there's a list of bank select values which you can use to set your patch assignments remotely via MIDI. I don't know Cakewalk specifically, but my very much cheaper sequencing software passes bank select and patch select MIDI messages, and Cakewalk will also. Including these messages means that every MIDI file you play will instantly reconfigure the patch assignments in your JV-1010, and you won't have to fool with SoundDiver or the JV-1010's front panel. (You have already found, of course, that Cakewalk does this anyway, so you just need to control it!)
These are NOT SysEx messages, but standard universal MIDI commands. Look for "Bank select" messages under "Control Change" in Cakewalk, which is how they're refered to in MIDI implementation. Compare to page 68 of your JV-1010 manual.
Look at
http://www.lilchips.com/ for Cakewalk initialization file updates which will allow you to select the JV-1010 patches by name from within Cakewalk.