Aluminium and copper are probably the hardest stuff to cut with a laser in the CO2 class as they just reflect most of the beam back. A laser machine in about the 3K-4K Watt range will cut 1 1/2" to 2" steel (correct me on this) but only cut about 5/8" aluminium plate if that.
The mirrors on my 35 watt laser to bend the beam around to where I want it are Aliminium so as you can see you probably won't be able to afford one in the class you want.
Unless you are rich and REALLY want one.
Rich.
I am not completely useless.......I can always serve as a BAD example.