I'd honestly have to see how such an amendment would be worded. From a personal perspective, I have no issue with suitably trained and vetted people having access to semi-automatics. I also have no issue with high capacity magazines, and would point out that at Columbine the guy with the 10 round mag killed the majority of people by a large number, so small mags are no defence there. My issues are making sure that guns don't end up in the wrong hands, not that they aren't there at all. This is why I'd have to see how it would be worded, the last thing that would be needed is an amendment that could be used to allow those currently banned from ownership to regain it via poor wording. If it was worded in such a way that only those with suitable training and clean backgrounds were guaranteed them, then I'd be fine with it.
The option you gave above wasn't actually what you stated previously.