For the patriot i was thinking along the lines of, 2xclass 4, 2xclass5, maybe a turret. The ship would be about 1 1/2 times the size of the original, have visably more armour and patrol police bases/the most distant fields in liberty.
I`m not thinking about Difficulty levels, i`ve already increased liberty to be higher than in the game, so it could fit in ok without affecting the defender. I guess the same could b said for the cavalier and drake too.