Here is a quick Borg mod that I posted about a year ago...
BorgMod.zip
It is designed around the kind of gameplay that you're describing. The Borg have virtually no research potential and have to get all of their Tech from analysis. It has zero level shipyards called Assimilation Nodes, Borg boarding parties that have Organic Regeneration so that a single Cube could capture more than one ship per combat, a Boarding Cannon to take out SDDs, and other such goodies.
It had a unique feel to gameplay and worked quite well. It was quite a change of pace to constantly be behind the tech curve. Have a look for yourself.
I haven't gotten around to addapting it to STM yet but I think I just might to se how it goes.