It should be noted that ME and PSP are both (a) a technology to implement a super-root over your entire system and (b) an implementation of said super-root environment that you do not control and cannot out out of. Trust Zone is only (a). Trust zone just defines a technology that may be used to implement such a thing, but it itself is harmless and does not actually do anything.

There are chips you can buy that do not come with any TrustZone code, and you may write your own to put in there, if you so wish

Thank you for these links, I'll look into them. And yeah, I do plan my upgrade to be quite expensive. For me, the work horse, has to be a beast to support virtualization, gaming and quite some editing - so in the end the price tag is not my main criteria.