There are tons of options, obviously, but a couple of my favorites are the Barber Direct Drive, the Lizard Leg Flying Dragon Boost (a phenomenal clean boost), CMATMODS stuff, and the Mad Professor Sky Blue Overdrive. I have a DC-3, which is a little mid heavy and I think a standard TS-9/808 is usually pushing more mids, so I like a flatter frequency response to not push certain frequencies, just give it more gain. I'm a fan of clean boost for that. I have always had great luck with the Barber Direct Drive for adding boost and gain without adding too much color. That being said, I have a good friend who has a DC-5 and he uses a Boss Blues Driver that I modified for him as his boost/gain pedal and he absolutely loves it. The mod I did opened up the frequency response and I think flattened the EQ a bit so that you hear the guitar and the amp, not the pedal so much. If you go the route of the Blues Driver, I would be more than happy to mod it for you if you would like. Anyway, that is part of the fun of amps, always trying to "make it sound better"! Good luck!