Why not look at hiring a Midi Guitar (Roland used to make them) and then get one of your mates to come over and record in several phrases for you.

OR buy a s/h midi guitar and learn a few basic chord patterns (ie barre form 1 and 2) and do them yourself

I reckon that would be far FAR easier and quicker than mucking around with any software, Melodyne included, which is not really all that terrific with multiple chord notes anyway.

Dennis