One shipset to another

Tempted to start playing again but had a question. Went back to spaceempires.net and re-dled all the old ship sets and alot of the new ones and the question popped in my head. Can I move a ship from one set to be used in another? ANd if yes, how? Actually, because I'm a fan of multi sizes (ie: Light carrier, carrier, heavy carrier) are the AIs in the various mods smart enough to upgrade from one size to another? Primarially I use BM but thinking of trying afew of the others or even just merging and making a super cool mod once I find one with the best (read most challanging) AI.. any suggestions on mods? I've DLed the current BM, Crimson Concept, Dark Nova, EvilMod and Scorched Space.

Ok, so more then just the subject, but you guys are good and helpful so I think I'm good.

Kyle