I think you are setting yourself up for a fall, you were inlove with this person not so long ago and you were hurting from breaking up with him 7 years before, I think you will more than likely get hurt again, I know this situation better than most here and have a much better insight, I think the other guy you like is a better option, you should tell him your feelings and not repeat mistakes of the past.
yeah I sound harsh but you dont need your head fucking with right now and considering how your son feels about his father it would be dmamging in that respect.
go for the other guy, tell him and see where it goes, it seemed to me you were made for each other.