Having a job is overrated for applications I think, at least in the current economic climate. If the firm you work for closes unless you are a partner there is little you could have done.
I would apply to the schools you originally planned to anyway, otherwise you will continually wonder what could have been.
As for taking a job in line with your career aspirations, part of the point of an MBA is to do that. You are unlikely to be able to do so unless you work an internship (if you can, do). I would have concerns about how welcome a prop trader would be in Asset Management though (at least traditional asset management) - not sure how you will convince them you lost your belief in alpha.
Look for a job and consider each opportunity, much like you would if business school didn't exist.