After checking with these companies.
Fuel Tanks
http://www.gas-tank.com/
http://www.floridamarinetanks.com/
http://www.lutherswelding.com/
http://www.sptanks.com/webdev/tanks.htm
Fuel tank sender [electronic]
http://www.hardin-marine.com/product...ge-senders.htm
We went with a local weld shop. Dave at D&D welding said when the tank goes above 50gal he up's the alum thickness from 1/8in to 3/16in.
The cost was $10gal. This fell very close inline with the companies above, but the turn around was 1 week unstead of 4 to 6 week's.