Well first off I would go with the VR6. A. its a VR6 and B. its a newer year than the other. Thats just me.
You need to ask yourself........
How many miles are on them? How much is the price diff? How much are you willing to spend? If the VR6 needs work then how much is it gona cost to fix? Is it a major problem? What do you want the car for? Is it a Daily Driver or something to play with? Those are just a few.