mschn:
So, since i'm switching such a large voltage source (relative to logic levels), could I have just as easily used PNP and NPN transistors on the anodes/cathodes instead of the npn+pFET combo on the anodes and npn on the cathodes?
You could have used a PNP transistor or power darlington, plus one additional resistor, in place of the P-channel mosfet. You would still need an NPN transistor to level shift the drive to the PNP transistor.