If your looking at cut-wells range have a look at the YG1's Alu-power, summat like a 6mm 2flute should give you good results but with these you need to keep the RPM down or the feed up when cutting plastics. The bests cutters I've used so far are OSG and M.A. Fords for Aluminium and plastic but that all depends on your budget and how sturdy your machine is.