Can't give any advice on guiding as we were self sufficient.
The only place we went that I'd recommend highly is Bariloche in Argentina, specifically Frey. It's a bit of a trek but the Refugio is nice with heaps of climbing info and mostly populated by climbers, so you might get a partner that way. In the town of Bariloche there's loads of adventure brochures. I'm sure one of the hostels could help you out. I imagine it's the same for most popular places in Patagonia.
If you are going solo then learn some Spanish, preferably from a South (South!) American.
Of course, if you partner up it will most likely be with Europeans.. Though Italians and Spaniards are most common and in my experience their English isn't great either..