Aluminum frame for the bed platform

I'm planning my next project: a bed platform/storage drawers/pull-out table. I noticed that all the write-ups use wood, but I'm concerned with the weight as it takes away from useful payload (e.g. extra water, fuel). I wanna use an aluminum frame (1.5" sq tube) for weight savings but haven't worked with this material before.

My question is: Is it possible to do a neat but strong connections with limited tools/skills, or am I better off just outsourcing the fabrication to some local metal shop? DIY welding of aluminum is out of question. Are those plastic connectors (e.g. these) rated for this application? The frame needs to be able to hold a 100's of lbs and withstand the sometimes-violent trail ride movement.

I plan to put on a 3/4" plywood on top and upholster it with outdoor carpeting, couple hatches for quick storage access, and maybe a few tie down points. Also need to find some Rubbermaid-style boxes I could use to fill the space around wheel wells.

 

Did you end up building this?
I am looking to do something similar - would love any beta you have...

 

I nteresting