Oh man theres so many good 500 series pres to have as a pair these days. I guess it all depends on what youre looking to record mostly.
I just got a 'box myself, i've been trying to hold off because i already have a rack full of nice pres, but i could resist no longer.
I'm definitely planning on a pair of 512c's for mine, but then, im thinking about using those for kick, snare and sometimes vocals.
The Shadow Hills GAMA would be sweet to have a pair of for the things you're looking to do, especially if you outfit them with all of the transformer options. I would absolutely look into them, maybe demo or have a listen to them somehow. They sound fantastic. thumbsup
I doubt you could go wrong with a pair of Great Rivers either. 500 Series Database | LunchBoxHero | 500 Series Database
Here's a database of pretty much everything available for 500 series.