Welcome to the world of Beetleweights! such a fun little weight class, one thing i will say though, if you're planning on using Alu angle like that try and make it as thick and as high a grade you can. Lynx at half throttle could slice straight through the cheese grade 3mm stuff, if you go onto Ebay you can find 6082 angle for peanuts and it'll stand up to a bit more.

It looks Huaaggeee BTW, is it just the picture? what are the dimensions?