Just noticed, but you have a lightened flywheel. Shouldn't take more than a sneeze and it'll be on up in the RPM range.
As far as the mod bug for Banshees, it is the worst in the world. I was planning a build for mine for when money starts rolling in. Simple porting and custom domes. I found myself pricing an entirely new engine for mine to reduce down time, long travel suspension, wheels, tires, front bumper, +2 swingarm, and more pipes within an hour. I had to stop myself.
If you don't keep it simple, it will add up instantly.
Also, if you're still undecided on domes, I'd call someone that can cut you some custom domes. I've seen some dynos with stock PD domes and similarly sized custom ones and I am very, very impressed. The place that I'm looking at does them for 85. Compare that to $50 for PD domes. $35 for a drastic increase in power, response, and efficiency? Why not?
Even though there are some very good benefits, I'd hold off on the entire head if you've never been on a ported Banshee. You may find that you have more power than you're used to. A 50hp Banshee feels much faster than you'd expect 50hp to. Mine is probably around 45 or so and I'm man handling it to keep it in line. The saying, "it acts like a 3rd arm" is nowhere close. Mine is about like controlling a 3rd credit card.