I climbed Izta and Orizaba in 2006 with Orizaba Mountain Guides. Oso (as he goes by) is the head of the company and holds the record for most Orizaba ascents. Besides climbing in Mexico with Oso in 2006, I also climbed with him and Javier (another of his guides) in Peru twice in later years. They are good guys and I definitely recommend them. If you go to the website, there are prices listed for different options. When in Tlachichuca, I stayed at the Canchola's hostel (which Oso had arranged). Joaquin and his daughter, Maribel, were tremendous hosts! I'm a huge Detroit Tigers fan and they were playing in the World Series while I was there. Joaquin and I watched the games together and it was a lot of fun (he is also a baseball fan). They definitely made me feel like family while was there. Hopefully Joaquin still has the Tigers shirt I gave him after the trip. But anyway, that trip to Mexico was one of the best climbing trips I've ever had so that's why I highly recommend them. http://www.orizabamountainguides.com.mx/about.html
Regarding the question from gotschall, it is not a technically difficult climb. So you can easily do it as long as you're sufficiently acclimated and proficient with ice axe and crampons. The danger (besides altitude, weather, etc) is that it is steep and can be very icy on the glacier. If you were to fall and be unable to self arrest....things likely wouldn't end well. When I climbed it, the conditions were very icy and Oso put in protection on a couple sections. Under the right conditions and with the appropriate skills, I'm sure this could easily be done solo without ropes. But that is very subjective so it's really an invidual decision. It's definitely a peak worth visiting though!