In reply to Will Legon:
I can't help with guides, but I did the circuit in June 2011 and stopped mid-way for four days or so and climbed Ausangate itself. It's a great area and a good trip to do.
We just used a horseman and two horses, hired from Cayetano Crispin in Tinqui (Tinki). He is the most well-known arriero in the region. We did not hire a guide, and it seemed the companies in Cusco operating it were quite expensive.
Horses were about US$15 a day including the horseman, so it can be done very cheaply. I'd factor this in when looking at guiding companies. Cayetano's son spoke a little english but I mostly organised it in my bad Spanish. His son organised a vehicle from Cusco for us and a night at Cayetano's hostel in Tinqi at the beginning and end.
The only thing a guided trip would have added really is a cook and meals, but I prefer to do that myself. Otherwise, you can't really get off route for the circuit, so there is not much for a guide to do.
Note: the hot springs were not that great :-/
Post edited at 10:39
