I've actually been able to see the selection sheets for awhile. I can't speak for the last couple weeks, but towards the end of december it was actually kind of diverse (instead of the normal jets/helos only that I guess has been going down for awhile). My week we had everything, jets, P3s, helos, E2/C2, and even E6. Beginin of Dec there were def more P3s than normal, meaning there actually were slots (1 or 2 max) compared to none at all which was the trend for awhile, although you never know. Every single week is different, and you never know how it's gonna be. I've seen 7 jet slots one week and 1 the next. Just do your best and let the chips fall man, there's nothing more you can do. Gotta remember a lot of it's timing and there's nothing you can do about that.
As for the marines, the selections I saw pretty much match up with what triplejayz said. Usually several jets in there, almost always more than the Navy gets.
I dont know of anywhere you can check out what the selections are week to week; our way of finding out was an inside deal that actually stopped lately. I guess just call someone you know at Corpus/Whiting.