Dime all the EQ knobs and see how that sounds. Then start "taking away" a bit here and there what you don't like. I've spent years running Marshalls and later my small Krank amp just with the EQ maxed flat out. I think some amp designers create the basic amp sound that way, not with the EQ on twelve o'clock. On my ENGL now I do cut the bass back a bit.
If that doesn't work, I think there is something not ok with the Peavey, because that guitar with that pickup shouldn't be giving you problems unless something is wrong with the wiring (which you'd know from a lot of noise).
Sometimes it can also be the speakers that are holding a whole setup back.
Extra EQ pedals/booster are more for fine-tuning - the basic sound needs to come from the guitar, amp and speakers and that should be ok first before meddling with pedals and more pickups.