... tell me at which level you get to each ship/remodel.

So far i have a lvl 21 BO, I have chosen the Z31 and had been told that at 20 i could
make the first remodel... wrong, I cant. The Spaz is there, unavailable of course.
I would like to know the tree/level up to Z99 at least. And if from there i would be
able to choose another thing or if it's a dead end.

Thank