larger sized alum extrusions

Hi,

Hoping someone here has some leads to cut down my search time.....

Does anyone know a supplier in the Philippines or SE Asia for, what I'll call, larger square hollow sections in 6061 T6? I'm thinking up to 12 x 12 inch...maybe larger...with a 6mm-12mm++ wall. Trying to rush some specs on a unique project and just need to see if something like this is readily available. I've worked with smaller stuff and it's easy to get. This is a new ballpark for me at this size. any info, suggestions, leads, load tables, etc very much appreciated!!!! This is for a 60' houseboat cat. We have frp amas (now the hulls) already and want to see if we can do the 4 major cross beams with a deck substructure as opposed to the steel i-beams and/or wood we normally use.

Best - Jay
Philippines