Through my business I have access to all the SS hoses, pipes and valves I need without expense. I just happen to have a 3 gal water jug sitting in the garage now not being used for anything else. The spigot is the same for the 3 and 5 gal jugs, so I can always remove the bulkhead fitting later on and put it in a 5 gal. For the rest of this year, I'll probably do either PM or extract. I don't think I'll step into AG until I've got a few PM's under my belt.
I just ordered 2 PM kits from Austin. One has 3.25lbs of grain, which would only require about 1gal of mash water if I'm reading right so far. The 5 gal jug would have too much headroom I think.