yuo gots 5 on 4.5 brah.
i ran 307's and 35's in the woods for years on the dirty 30 and c-clip 35, i wasnt gentle, and always kept spare shafts and never needed them.
lucky i guess.
i just put the 8.8 in the rear and im glad i did. piece of mind.
what do ya mean "where can i find offroad rims" ????
just go lookin dude, get some 15x10 black/white steelies and go!
you will be fine with the 307's though, it will be a pig, but just use 4low in the woods and you will be fine.
(super 35 kit) is def something to look into.
your front 30 is fine.