Personally I’m too paranoid about security and sus of Intel to be comfortable with vPro but you do you.

That said, I’d go for 1, considering you already have thay 6th gen on hand in case you need a spare.

Otherwise 3 or 4 (whichever is available on secondary markets for a decent price) and hang on to that Pentium in case need arises. Doesn’t sound like the extra power draw of an i7 is worth it for this build.