Newby questions about vBulletin and mySQL database(s)

[BonsaiNut]

I have had my site up for about 9 months and everything has worked flawlessly. However a week ago I exceeded my host's size limits for my mySQL database, and my host has since blocked access to the DB. My host currently limits mySQL databases to 100MB in size, though I can have up to 50 separate DB's under my hosting agreement. Given this situation, I have a couple of simple questions about DB Administration and how DB's work with vBulletin.

1) Can I have one forum that is supported by multiple DB's, and how (in general) would I configure the site? Would it be as simple as having a single forum category be its own DB? Would configuring the forum this way impact search functionality, site response time, or have any other negative or unforeseen consequences?

2) Would it be easy/better to just move to a new server host that offers a 5GB size limit on mySQL DB instead of my current host with the 100MB limit?

Thanks for helping me on my journey of self-discovery