The strut will support a 3bbl system if you build in support columns to help with the load. It really is every bit as strong as 11 ga tubing.
Platt has locations for pick up, but nothing in SoCal.
Locations
I want to like Grainger...but they ALWAYS kill me on the price.
Good luck with your Nano brewery. Post something when you have it.
The closest one is near Bakersfield. Shipping may be killer. Just got the quote from IMS for the tube stock and it's super reasonable, and I wouldn't need to ship it. They may also have the strut but I'll have to go down there and find out. If my welder friend-of-a-friend comes through for cheap, that will be the way to go.
I'm actually most concerned about the joins on the strut. I'm sure the steel will hold up, but not as much with the various fittings that hold it all together.