I kinda like Option 3 but with an additional twist, which I'm not sure will sit well with you but an idea is an idea.

I seem to recall Rongi sending an email to the contestants at the beginning with the theme for each week all the way to the end (or something along those lines). Depending on how many weeks/models there are, I instead think you could send the contestants the themes for the first half, say 6 weeks, and then do an elimination of the models with the lowest points. At that point, the remaining contestants get the themes for the remaining weeks, and given a week/fortnight times to gather their shots before having a final elimination at the end.

Either way, a new way of doing things always keeps a contest exciting.

(Long-time lurker of ENTM...)