I'm not sure I'd really try wheeling with only 2wd personally...
a d35 will be fine up to 31s, above that, you're likely to break it. a c8.25 will cost you $200 or less at a junkyard though, so if you're serious about this, wheel it till it breaks, bolt a c8.25 in, continue. Personally I would not spend money on gears and a locker for a dana 35, just gears or just a locker will cost you approximately the same as getting a better axle, i.e. getting parts to set up properly with a new axle+gears+locker will cost you 1.5x what setting a d35 up will cost, not including labor and random nuts/bolts/external stuff, and will last longer.
No idea on what gearing came standard, but almost anyone else here will probably know that off the top of their head.
EDIT: I'm not locked yet because I knew lockers were expensive. Didn't realize how expensive. It'll cost you 300-900 for a locker, from what I'm seeing, don't bother putting one in a d35 IMO.