Might be worth getting a valve pedal, like one of the Blackstar ones. They do one that will do a 2 channel amp, and from what i've heard they can do a good gainy sound.
If you do like Antag said and set the SS amp to clean, then use the pedal, you might find you'll get a decent tone.
Trust me on this too, i recently upgraded to a valve amp (Orange Tiny Terror) from numerous SS amps, and the difference in sound and feel is astounding.