Honestly bro, its up to you. It's personal preference and $$$$. You can make a killer trail bike out of a banshee with the right pipe and port set up & of course suspension. Stock for stock the 450 would be a better set up. If you want to be original and different, I'd say go with the banshee and set her up for trails.
As far as cooling a banshee, throw in some Engine Ice and add a billet impeller and that should help a bunch.