you really dont need to use the water fitting on the turbo i ran one for a long time with out one (t25) on a past junkyard turbo build i did.
but i do remeber buying fittings for it i went to homedepot with the turbo in hand and went to the plumbing section and i found what i needed but i never used them haha. good luck with the t25 those are great turbos for stock motors with a little boost the boost is almost instant and holds pretty well your gonna enjoy it im sure.