I'd be happier with either honestly. The 3G Edition comes with the memory card, and I think the free month of service right? I hope they update it where you can play your PSOne games on there. Just bought Final Fantasy 7/8.
Edit: Just did some research. The Wifi Vita is better in my opinion. I don't think I would ever use the 3G service especially since it's an added price every month.
I have the 3G and I agree. Plus, you only get the free month after you've paid for the first month.