I'm planning on picking up some logic level MOSFET's as soon as I see a batch going for cheap. I've seen a few N-Channel models, logic level input, with max voltages around 60v and a current capacity of 10A.. those would be the right answer here I think.
Right or wrong, cleaned up the wiring, and up to 34 watts now..
EDIT>>Went up on ebay and got a batch of 20 N-Channel Logic Level MOSFETs for seven bucks shipped. 11A, 60v maximum. Time to get my feet in the waters of MOSFET... these will switch a LOT faster, and since it's Darlington, I'm never reaching full saturation on the output stage, right? Also a lot more headroom power-wise. Seems like I've been spooked by the scary looking symbol too long..
http://www.ebay.com/itm/160768659447?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649