Just picked up a GP5.
As already noted elsewhere, the octave is crap, but there are some really nice sounds to found in there. I'm waiting on an Mvave chocolate controller, so we'll see how it stacks up after that.
there are many lowish gain drives that would fit the bill.
The first stop for me would be to try something like the full sized spark as mentioned by Lozz
1: Rickenbacker 4001 or 3 ( I'm not fussy) but in Natural with a maple board
2: A maple boarded fender PP
3: A decent splitter bus and driver
4: A Marshall 810 - either MBC or VBC
5: Sennheiser G4 IEM rig