Pet Supply Warehouse is the place to look if you need tanks/stands or equipment for sure. I think you could always call them before making the trip out from Indiana.
As for PSP, my experience is that the North Huntingdon store is the (relatively speaking) best, then Monroeville, then Greensburg. It's only 5 minutes from me so if I'm desperate and in a hurry I'll drop by there for something.
As for livestock, the main place I go to is All Oddball Aquatics in Pittsburgh, definitely worth the trip.