If you want a rush paragliding it's defo available. The guy I flew with there is a previous world champion and that is where he won it so it's basically his home turf. I still have his business card if you required details.
He'll do stunts etc with you if that's what you want. You'll soon know what a rush is when you are in a spiral pulling a few G and your face is almost falling off lol.
On a side note if you want a good rush try "sea biscuiting" in Mendoza. Hardly anyone does it, instructors included.
But yes, the buses in Argentina are way better than those in Bolivia and Peru. Cost isn't much different either. I'd take a look around the station whilst there to see which company's have the better looking one's. Can't remember all the names off hand.