Denver is at altitude. Altitude is thin air. Without going crazy and to remain as trouble free as possible while restoring performance lost to the thin air I would only do a couple things to start, then ride it for a while, determine what you want to improve and go from there.
1. have the head milled .030 to restore the compression
2. get a Uni airfilter and remove the airbox lid
3. remove the oil injection and premix
4. get a decent used aftermarket pipe and silencer
5. find someone who knows what they are doing to rejet it for you after doing these mods
These are pretty simple, cheap, and will not effect dependability if done and jetted correctly and will do a nice job of waking the bike up.