I went with Strait Line performance with mine and did a SLP on my fathers. Just watch your compression ratio on whatever you go to. May have to mix your fuel. Both are 13.5:1. I was very impressed with the SLP Head. Along with a port and polish, new vforce reeds, pipe and can; it really hauls ass.
Not taking anything away from the aforementioned vendors, but on my 05 Rev Summit X I ran a Dynoport single and RKT head with 14:1 domes. Jetted it with 380 mains and it performed very well. One caution - the sled was never ridden in the flatlands, only in the mountains. A sled run in the flats would need a lower compression head or blended fuel 50/50 C14 and 91 premium, and likely fatter jetting.