I'm think of getting a new pedal for my set-up, i'm looking for a RHCP tone or a more classical rock tone. So i was thinking maybe an overdrive pedal, but would that work with the vox if its not 100% tube/valve. also maybe a Big Muff Pi. any ideas?

on a side note, what would be the best pedal to make the vox a metal machine? (for a friend, who bought the vox after i did, and wants to play metal now...)
My Gear
Agile AL-3000 Prestige Slim Profile Neck
Schecter C-1 PLUS
Washburn WD18SW Solid-Wood Acoustic
Vox AD30vt with the VFS2 footswitch
Fender PT-100 tuner
Vox wah pedal
english muff'n

its an awesome pedal and can do anything from overdrive to almost fuzz
Fender '82 Walnut Strat
Fender '65 Twin Reverb Reissue
Voodoo Labs Sparkle Drive
EHX English Muff'n
Boss DD-6