Mission specifics:
I am looking for a "tactical" set up for chasing rabbits across the Nevada desert. It  needs only to accomodate shotgun shells. I don't need armor, AR pouches, grenade pouches, or the like. A few accessories pouches or pistol mag pouches maybe.
Camelback compatible a plus.
Thanks in advance for all yer help.

Get a Warlord Version 4 with the 60 shell insert for the Admin panel.  You'd be a uber-tacticool heavily armed bunny hunter.  Elmer Fudd would worship you!

It dose not seem that your gear needs to be bomb proof so i would say just get a cheap vest from Cheaper then dirt and then get a few of the shotshell holders and put them on wear you want. the vest already has a slot for a bladder in the back but it is not super strong. get a few utility pouches and then put them on to. if you decide to go with the pistol mag pouches then the only thing i will recomend is Hsgi. CTD pistol mag pouches are about useless.  keep in mind that this is not going to be a super quality rig, but if the only thing your faceing is rabbits, then it is cheap and will work.
if you want this vest to double for anything like combat or survival then get better stuff.

A friend of mine did something very simialr to this for just casual shooting. he has no need for an uber tactical, bomb proff rig that hold everything. he just wanted something cheap to hold a few mags for a few diffrent guns and a couple of water bottles. it works good for what he needs and was cheap.

hope this helps you. i kinda rambled.