dedicated mulcher
Samson,
As you probably know you are in one of the harshest environments for mulching to the the slopes, elevation, rocky terrain, etc. A Fecon FTX148L is definately going to be your best bet. Make sure you get it with the deep sump oil pan to get the best use on slopes. The fecon mulching head is by far the most durable and will hold up to the rocks better than any other brand. Durability in your environment is up time. The FTX148L has loader arms, the most available power of any machine in its class and the lowest fuel consumption as well. The performance will amaze you.
I know Power Motive Corp in Denver and Grand junction have them in stock and rent them as well as sell them. Maybe rent one for a month and then make your decision. Good luck!