I think you have a pretty good list. You have pretty specific criteria, I'm not sure I could do a better job finding matches. I will say when viewing the "length" of a tent... not all tents are equal. Wall height at the ends can play a big role in how long the comfortable length is for you. Also, if you are comparing to the length of your single tent, the additional room of a 3/4 person tent may make length issues less apparent (you can lay somewhat diagonally). It would be a good idea if you could stop by a retailer (such as REI) that has some of these tents set up for you to check out how spacious it feels inside.

I will throw out a suggestion that does not hit some of your criteria but nails several others: Tarptent Hogback

It is a 4-person 4 lb tent. It would be spacious for the two of you (if you are ok with the length), but it has very small vestibules. That means it is going to have a smaller footprint than some of the other tents you are looking at. I often find it challenging to find a large enough spot to setup big tents. It is double walled, but not a quasi 4-season tent like you are interested in. The rain fly can be rolled up half way to give you views on rainless nights. Tent sets up much more taut than other commercial tents I have seen (I don't think the rain shell could touch the inner tent during wind gusts). It is free standing with the optional crossing pole. I'm not sure what you mean by diagonal zipper, but the zipper is easy to reach because the vestibule is very small.