Congratulations Kman!
Unless you know sheep and the country they live in, going guided is a very good choice. Especially since 95% of the hunters on this site will never hunt Rocky Mt. Bighorns! It is pretty much a OIL experience for all of us, if we get even one chance.
I don't know Colorado outfits, so I can't comment on that. But
one thing I will say, having been guided for Rockys in Wyoming, take every opportunity to get everything out of the hunt you can. I had a chance to kill a decent ram the first night into sheep country and I passed, because I didn't want to cheat myself out of a real sheep hunting experience. Even after waiting 5 of the 10 days to kill my sheep, I still felt like I left too soon. A sheep hunt is so rare and special, do everything you can to make it that way. Get in shape...shoot a lot and get to know your gun well. Take lots of pictures, and even video if you have a chance.
Do your part and you will have an experience you will never forget.
Oh and be sure to share it with your friends on MM!