I dont mean to rag on your gear... but the amp is going to be difficult to get a good thick sounding tone from.
I had a valvetronix. I've had Twin's, CC2 AC30 and AC15, and now a Fender Vibrolux and a AC15hw.
You will have a hard time finding good thick overdrives with that amp. I would suggest that you either get a new amp... or invest in a nice overdrive pedal. The FUCHS Plush Drive is not that expensive and it has lots of flexability. You will find it easier to get thick creamy overdriven sounds with that pedal than others.
Maybe a Fulltone Fulldrive?
Stay away from treble boosters or marshall like pedals as they add too much treble to your already trebley amp.
Solid state amps are great practice amps and can be great live amps... But trying to get one to sound like a great tube amp is like trying to get your honda civic to handle like a Ferrari. I am not saying the valvetronix cant sound good... They can get some great tones... But it will not sound like Joe's $20,000 rig.