I'd put something with a little more personality as the room mic, and put another 451 under the snare, or taped together with the 57 on top, with another 57 below. They can provide a really awesome snare crack when paired with a 57. Also, I'd suggest substituting the 421 and Beta 52 on kick with a D112 or D6 and SubKick(if you have an old speaker, you can also wire it really easily to become a SubKick for little or no money, and sounds great). I've never really liked the Beta52, so I'd always prefer a D6 or D112. Also, if you have a little more money, I'd suggest throwing some type of LDC in a tunnel a few feet in front of the kick, giving it a great thump. Oh yeah, and I'd definitely go with the 421's, or D2's and D4's on the toms. I prefer 57's to Beta 57's, and even then, I'm not in love with them on toms. If you find them cheap, you could also use an ATM25 on the toms, they work awesome too.
So, here's what my version of your list would look like:
Room:
Snare Top: SM57 and C451
Snare Bottom: SM57 or TLM103(really awesome here)
Kick Drum: D112, Subkick(or other speaker mic), and an LDC(TLM103, 127, 149, 87, etc.)
Hats: SM7(sounds killer and is REALLY useful on other sources, too) or C451
Crashes: AT4033 or 4040
Ride: C451 or KM84
China: C451 or KM84
Toms: MD421's, D2's and D4's, or ATM25's