If I understand correctly, you have 1 sprite that you simply change the animation to.
If that is the case, you could store each ship in an array.
Something like this:
[
[ ship,fireRate,shield,speed,special]]
which translates too:
[
[ship1,10,5,5,none],[ship2,15,6,2,rapidFire]] and so forth.
You can then persist this array with local storage.
When a player changes ship, simply grab the right values from the array and apply it to your sprite.
Cheers