JJ's are great, thats what i have in my SVT II, well, the pre section, wish i had stuck them in the power section too, but that'll happen in due time
www.eurotubes.com
Bob is really easy to deal with, tell him what you want, and what kind of sound your looking for (as you said, more transparent) and he'll set you up with a good set of pre tubes

(cant really change types of power tube, well, not easily anyway)
As MrLizard said, power tubes are possibly the reason for it running too hot, if you can, maybe try a 12AU7 (ECC82) instead of a 12AX7 (ECC83S) in the driver section, you'll lower the gain going to the power section so it'll stay cleaning sounding, but a bit quieter (im sure thats right anyways? )