Well, I've applied for St John's myself this year for history and got rejected. It's still is one of the wealthiest colleges in Cambridge, although I've heard of their financial troubles, too. The question is, though, will the college charge you more because of that? I mean, you'll have to the full fees anyway as you're an international student, so will it make a difference?
To try at Trinity would seem risky to me (always bear in mind that in the next 1-2 years applications are likely to rise a lot, I think, because everyone wants to get in before Labour allows the unis to charge higher fees). St John's is fairly similar to Trinity I believe, very beautiful indeed, also a big college, so I'd say try there. Go and have a look at it at an open day.
Which subject have you applied to, by the way?