You shouldn't have any problems just putting a new handle on it, whether it's the inside handle or the outside one. Once you take the interior panel off the door you'll see how it's connected and you should be able to figure out how to take the broken one off and put the new one on.
Here's a link to where you can get a new one:
http://www.gmpartsdirect.com/catalog/frameset.cfm (drivers side is the left side one)
I'm suggesting you just get a new one since with a used one you'd never know how long it would last and if you're gonna go through all the trouble of changing it you might as well get new since they don't cost that much and you won't have to worry about it breaking anytime soon.