[artdutra04]

If you possess a means (such as a sheet metal bend/brake) to bend the edges of all of the 1/8" aluminum components into flanges, you'll drastically increase their strength.

Now if you do decide to go this route, you can't really use 6061, as that doesn't like being bent (you'll get stress fractures everywhere and the joint will be as good as useless).

A more preferable grade would be 5052, as you can usually bend this with a bend radius equal to the material thickness without any problems. However 5052 isn't real fun to machine, so everything would have to be punched or cut out with a laser/waterjet.

It's all about the design trade-offs.