Best way to read the regs is to print them out, and highlight all the parts that are applicable to you, and re-read, and re-read. And if you think you have a creative interpreatation run it past stu, and he'll tell you if your cleaver or not.
As far as a cage, just get one built to CAMS specs, as that will easily cover you for and AASA events, and CAMS events.
You also need a internal and external isolation switch.