PVP,gems abnd enchants advice..Follow

First of all, what kind of PVP are you going for? BG's, arena (2's, 3's of 5's?), world pvp or duels?
If it's somewhere your opponent expects you to be there and shoot him (actually every situation except world pvp), you might wanna get a decent amount of stam en resil before you face them (!also, having high health might prevent you from being primary target!). So your gems might include Stam and resil. Once you have enough pvp gear, just gem what works out for normal dps situations (Agi, agi+crit if socketbonus is better than +4 agi). Do NOT however, gem ArP! This maybe weird, seeing as the MM ArP hunters in pve have great results, from the moment your foe's have some resil, ArP doesn't work out.
As for enchants, just take whichever enchant you would take for dps. Don't forget to pick up a Titanium weapon chain if you skip the anti-disarm talent.

And I have to dissappoint you, if you go arena, BM rarely works out (only in certain setups), but you can ofc try :).

Well, in BG's, all specs work out. And the stam isn't really that important then, you'll respawn anyway. The main reason you want more hp is so that when people mouseover you, they don't instantly think you're a sitting duck.
You do want some pvp gear though, everyone with somewhat higher gear will just run through you now. Gem and enchant it with Agility as much as you can. Agility is the best pvp dps stat for you.

I would go with this, but some will disagree.
http://www.arenajunkies.com/talents/hunter/0_15_56_2/