Just a few I had saved...
http://www.regal-plastics.com/austin.html
Regal Plastics for acrylic and Weld-On
http://www.hardwarestoreinc.com/
This is a local mom and pop hardware store (to which I have no affiliation)
but if it's beyond the realm of Lowes or HDepot you'll find it here in regards to plumbing supplies (all size hose, spaflex by the foot), nylon bolts, fittings, etc., etc.
It's a DIY'ers heaven. lol
http://coralreefbazaar.com/store.php
Another good local source for the "harder-to-find" items.
I'm sure you've found the local stores but I'll list two.
http://www.rivercityaquatics.com/
Great people.
Carlos and his staff are always there for you (buying or not).
(Where I come from it's called "doin da right ting") lol
http://www.kingfishaquarium.com/index.htm
An "up-and-commer"