Andean guides can be a bit of a crap shoot, especially if you haven't been there, or similar areas before, and have no altitude experience. There are some good guides and agencies, but plenty (ie. more) not so good ones. Even the good ones tend to provide a rushed itinerary, promising more than they can deliver, with not enough time at the start to acclimatise properly. They also feel pressure to run trips to peaks or routes that may not be in good or safe condition (ie. Huascaran) because they really need the money.
In your situation, you might want to look at something like: http://www.alpineinstitute.com/catalog/ ... xpedition/
This is a great area (I climbed there in 1999) - interesting mountains, nice village and some culture etc and not as touristed as the Huaraz/Cord.Blanca area of Peru etc. If you go early in the season, the 'headwall' on Illampu is not difficult, just straightforward 50deg snow ice for a couple hundred metres max.
Last year I also climbed Ausangate in the Cordillera Vilcanota. This is also a great area and a good peak, but the few guides/agencies I saw for the area were not good. I normally like to recommend local companies over Western commercial companies, but for the inexperienced
so many Andean agencies are just not good enough.
This guy wrote one of the main guidebooks and runs some good trips: http://www.andes.org.uk/expeditions-and ... s-peru.asp