I did it for my "Olympus Mod" Its actually quite simple. There are two entities that you need... You need the ones like squadTECHcombat, and the ones fighterTECHcombat
Combat is fighter, bomber is well..bomber
Squad files are the basis of how the squad acts, things like, how do they attack, what do they attack, how many are in a squad...
Fighter files are about the stats. These are the things that you may want to look at...the ST's are just like other ships in that their entity files are nearly identical.. They have weapons, (more than one if you want them to) and speed, abilities (if you want them to have them) and many other things...
For my mod, I made two entirely new types of ST's...I made some for the Advent ship called the Judgement, which are meant to be spammed.. upgradable to 300 (it give the illusion of power,) but at the cost of individual value...they are good, but are about the same as fifteen normal squads...(they have been nerfed to the point where any lower wouldn't do anything...)
Then you have the ones for the TEC, these are a little more than twice as powerful as before...
Eventually I will start work on some for the Vasari, but I'm not there yet...
Also, if you were in the mood for killing you computer...change the mesh to something like the Kol, and then increase the command points of all capital ships... The point here is (aside from getting the blue screen of death, and I am not liable for any crashes this may cause) that you can change the mesh. The reason could be that you want to do something that would make it obvious to the player that it is not the same as normal ones...
If you need additional help on anything (except for texturing) PM me and I'll be glad to help...