Amp tubes, dudes

I've never used these myself but know of their existence as these converters to use 6V6 or EL84 tubes in a 6L6 or EL34 amp, lowering wattage and headroom before distortion.

http://www.yellowjacketstc.com/

I think an overdrive and a boost is a good combo. If you can find two pedals that work with your amp, you can get the classic 3 channel (clean, distortion & solo boost) setup. Most common overdrive probably being the Ibanez Tubescreamer and the nigh on a million permutations and then you got your clean boost variants usually based on various different 'chip sets'. Most common are your old style 'treble boost' based on a Germanium chip or others based on some 'jfet/mosfet' chip design. There are thousands of permutations.