would I be better off going with either an AMD system,,,Am-2 OR am-3?
Going with an AMD system won't necessarily avoid the problem. UEFI is the newest standard for BIOS. What you need to find out, is can you turn off secure boot. The spec for UEFI says you should be able to, however, before you invest in the system board, investigate to see it the boards you are interested in , secure boot can, or can not be turned off. Different UEFI (BIOS) manufacturers call legacy boot different things, so it takes some understanding to sort it out.
I have been reading some people have installed linux in secure boot mode. It is not trivial, and don't rely on that, unless you are very familiar with UEFI, signing keys and all the stuff that goes with it.