Hi Steve ,
congratulations.
Bet you can't wait till the 2 weeks are up. haahaa
Take your time about what add on you want to get.
It's easier learning one then adding the other.
I made that mistake a few years ago. Bought a friends
Roland VA7, few weeks, later the Technics KN7 came out,
VA7 sat in the corner for the next 2 years till I decided to sell it. I never gave it a chance.

As for software for you new pc. Should you happen to decide to give Band in a Box a try, it comes with a seperate sequencer called Real Tracks. Doesn't get much coverage, but it should.
Real Tracks is included with BIAB, so just keep it in mind.
There's also a RealBand forum over at PG Music.

For home studio, you've even got options like One Man Band realtime arrnger software. It loads & plays yamaha formatted style data.
Styles usually need a fair bit of tweaking to get them to work with whatever soundsource you want to use, great way to get access to yammie styles though. It even has a basic sequencer, a style editor, arranger page where you type in chord progression & style parts, save as midifile.

http://www.1manband.nl/

At least you've got some time to do a bit of homework before you need to decide.

Congrats , once again.