Wagner has this new model, which I saw at Costco for $220:
I know some people suggest renting a heavy-duty machine, but all I see at our local rental place is a Graco for $110/day, and I don't know how long it's going to take me to do the whole outside of a house -- learning curve and all that. IAC, the machine available for rent seems to be a sprayer only, and I think (but I could be wrong) that a roller might work better for the grooved plywood siding we have -- and a roller might be easier not to make a horrible mess with.
Perce