This is my first ar build I'm down to the last parts that I need to get. I'm having trouble deciding what buffer weight I should choose. I'm planning on using the sprinco green spring but the weights I'm not sure of. I'm planning on shooting unsurpressed until I get some funds for a suppressor, should I go with the H2 or H3 buffer?

If your using a carbine length buffer tube, and want a mil-spec spring, you should get the white one.  The green one is for a rifle length buffer tube.  For shooting only unsuppressed, I would start with a 3 oz. std carbine buffer, and only change if you have problems.  You can buy buffer weights from KAK industries and change it later if necessary.  If you end up adding a suppressor and always shoot suppressed, you might want a stiffer spring/heavier buffer and/or adjustable gas block.  Other than an adjustable gas block, don't start out that way, or you may have cycling issues unsuppressed.  I've given up going back and forth between suppressed/unsuppressed, and have dedicated rifle/suppressor combos set up for a specific configuration.

The buffer tube I am using is the BCM intermediate A5

Ok, I assumed you would be using a shorter carbine buffer tube for an SBR/AR Pistol.

I just built a pistol with that barrel for my brother, put a Geissele Super42 with an H2 buffer in, runs perfectly.

H2 and Sprinco Green will be fine.

I have a DD 11.5" but i'm using a SupArms adjustable gas block and a JP silent captured spring in H2 config. It runs but suppressed and unsuppressed flawlessly.

Get an Odin Works 'Heavy' Adj Buffer (Or an H3 and scrounge a Carbine so you can mix and match if you want to do the labor) and start light. Then add until you get your 3-4 O'clock. Don't be surprised that when you add the Can, you'll need to go as heavy as you have (which is why I like the Odin Heavy Body- it goes up to 7.x oz with three Tungsten), and maybe even an Adjustable Gas Block. That, of course, is only if you want to nerd out in the weeds, with "tuning".

Carbine buffer should be fine