Get thyself over to the Woo Audio Amp owners thread. You will have a great deal of advice on tubes.
I'm also a recent owner of the Woo WA22.
Rectifier Tubes -> I have tried the Sophia Princess 274B and experienced hum biased towards left. I am now using EML5u4g with no hum and similar sound quality to 274b. I'm also now considering NOS 5u4g like 1950 RCA (has any one tried these?) / Mullard CV378 Straight Brown base (I'd be very interest in anyone's feedback on these).
Amp getting hot -> I found my amp runs cooler after I added a 2000watt capacity 240v to 220v step down transformer ( I'm In Australia and get up to 250v mains utility voltage) I got mine from http://www.tortech.com.au/category/other-stepdowns/
Driver Tubes -> I find the RCA 6cg7 a good match with the LCD2. There is a definite increase in bass tightness and attack over the GE 6sn7gtb.... over all a more crisp sound which is good thing for the inherently darker sounding LCDs (6sn7 does lack base control and makes the LCD sound a little fat, but 6cg7 is not as warm and am not sure if the sound stage is as deep. Seamaster's notes has helped a lot.
Source-Pioneer PD91+Trichord Clk 4 and NC PSU | DAC- Benchmark DAC1Pre | Interconnects-Sharkwire Pure Silver | Amp-WooAudioWA22 (EML5U4G|Sylvania7236|RCA 6CG7) | Headphones - Senn HD650 + Audeze LCD2