What're you shooting now? If you've a cut away riser and shooting a release with a prong style rest vanes will probably clear fine. Especially if you had a drop away rest. If vanes will shoot out of your bow without hitting your riser, go with them. You won't have to worry about rain messing them up. If you're getting contact, or close, you may want feathers because they'll lie down when they hit the riser and preserve the arrow flight. You said you want the most forgiving arrow you can get, so I'd recommend going with 4-5" feathers with a helix. The thing is that the larger you get with the fletching it's more forgiving, but it also slows your arrow down more. You can go to Trueflight Feather's website (www.trueflightfeathers.com)and they list some of the benefits of feathers over vanes. That may help you make your decision.

God bless,
Brandan