If your real motivation is heat, then +1 to what SoCal-Pappy stated. Also consider an oil cooler.
Your profile does not indicate what you ride, so I cannot comment on power. I'm satisfied with thenewer motor (96), and I personally cannot justify $$$ for more power. But then again, if you've got the $$$, ....
Pappys recommendations are spot on. As UGlide said you don't speak of what you ride but after I made the stage on upgrades I am perfectly happy, even with the 88.
Bore out the cylinders (95"), add Kuryakyn flat top pistons, TC-1 cams, Harley SE Tuner, SE Intake and Power Curve headpipes. Then have it dyno tuned. Zooommm.....