For the widener i don't like the plugin i use, it works but it does not sound pleasent to my ears. The idea is using my comps for mix bus and to have the widener with it in the analog path. It does not need to be very complex with a lot of features so it could be not much expensive. Beeing able to center the low end would be super cool though, and M/S.
The limiter it's a bit tricky cause i have a free plugin that is stunning so i don't need one but if it can be added to a widener and works as amazingly as my plugin it would be tremendous.
I already have two CP5176 and two MU524, they sound super cool but matching them is not super easy, plus a stereo comp should be less expensive maybe. I would be more on the stereo fet.
I would love an analog chorus that i can use with my guitar or for mixing. I have no valuable reasons for that but i would pull the trigger for a pair.
A 10 slots lunchbox with faders pan and aux sends in differents racks

Some 19 racks (everything tubes)
Also maybe some other kind of products like a bass head amp (solid state first), guitar head amps...