I had the same amp years ago
Did you do any mods to the amp itself? I've been looking into getting JJ 6V6s for the power tubes and some high gain preamp tubes to improve the cr@ppy o/d channel and make the amp break up a bit earlier (it also lowers the wattage to about 28W instead of 40).
And i've been doing a lot more tweaking with my mt2 and the tubezone and i get a much fatter sound out of it which seems to be doing it for me now, so i may just keep the mt2....who knows.
Also, my new bkp cold sweats have just arrived so i think i'm going to have to redecide what i do once theyve been installed and see how i go.
A couple of pedals that might work for you:
Electro-Harmonix Big Muff.
Homebrew Electronics Full Metal Jacket.
I looked into the eh big muff a while ago, but it didnt really cut it, but the HE FMJ, that is one nice sounding pedal, but a bit over my budget though...maybe in the future.