I believe rockdoc said his son did some - not sure if he'd be up for something that size.
I was looking over a year ago, and came up with a few places in the sarasota area ... If you don't need acrylic - why not go with polypropylene?
There is a place in the cape that builds polypropylene tanks for all sorts of commercial applications. I've talked with them before, and they would even do custom stuff.
--marco