Hey, I'm in the same boat, although just applying to Oxford and Cambridge. Just started studying for GMAT, so not sure where I'll be in September.
There's a good thread called
Oxbridge 2011 applicants that has just been started. You can also sift through last year's
Oxbridge thread. Another thing to consider, mentioned in the 2011 Oxbridge thread, is scholarship deadlines. Some of them are really early and would require a R1 application. This is my first time attempting links, so if I screwed that up royally, they're both in this same forum (international b-school applications) and both have pretty recent last posts.
I would also check out the
Best MBA application tips thread, which has some very good insight on the MBA application process. One of the things I took away from here that is making my strategy a bit more complicated is that your applications get better as you complete more applications. So applying to your top school in R1 might not work in your favor since your applications might significantly improve in R2 or R3. This thread is in The B-School Application forum.