My advice would be to build your rhythm section FIRST, rather than expect one VSTi to do it all...

BFD, DFH2, whatever works best for you on drums first (if they suck, everything sucks!), then basses (Scarbee, etc.) then guitars, and so on... Rather than get a VSTi that does it ALL, recognize that you probably won't need 808 drums and techno loops, but you DO want a variety of brushed drums, or whatever your priorities are. Specialized VSTi's allow for more choice in the areas that YOU are most likely to need.