I've done a few of these. The first one, I used wet hops throughout. I tasted like a chlorophyll beer to me lol. Others loved it. My recommendation is to bitter with pellets. Toss your wet hops in at the end of the boil and whirlpool. In two to three weeks, your left over wet hops will be dried leaf hops. Dry hop with the freshly dried hops.
I think with the wet hops, 5-7 times the weight of dried hops is realistic. It's really just a crap shoot since you don't know your alpha units either. Just make sure you can easily filter them out whether you put them in a muslin bag or hop spider or something.
I might add. Another time I did one, I had a few friends over. As we harvested them off the bine, we just tossed them in the kettle. That was fun. I find that wet-hopped beers are more for the novelty, so fun is good.