First off - gnarly avatar. One of my favorites.
Second - with practice, you'll be accustomed to using a 5 stringer tuned B-G for all different tunings (you have the extended low range down to B, so you can play with your guitarists down to C. Just imagine it as a "capo" on the first fret across the board. If the guitarist is tunded to D standard, then your "capo" moves up to the 3rd fret, and so forth).
Thridly - A great 5er is any LTD F-series bass. They play great, tighter string spacing, thinner necks, and great features for the price. Alot of metal musicains love LTD. Additionally, the F-series basses has a 35" scale, which makes a world of difference in terms of tone.
As always, YMMV.