I bought a milsig hydration vest and have used it paintballing three times now and it is pretty amazing.
Plus it is on sale right now for only $60 (I paid $90). The bladder holds 2l of water which I still didn't use after playing at a big game at wassaga beach for about 6 hours.
http://www.milsig.ca/store/index.php...roducts_id=581
They also have another nice looking vest but it doesn't have a hydration pack which I will not buy a vest without now :
http://www.milsig.ca/store/index.php...roducts_id=305