I'd make sure the drummer tracked at 44K and keep it that way throughout the
project.

Sound quality will be as good as the drummers' chops, sound and tuning of his
kit, mic choices/positioning/pre-amp choices/convertors allow....then when you
import those files into YOUR 44k session, you wont lose a bit of that sound
quality and all processing will be be fast and painless.

Good luck! Dean
Why all the scuttle-butt?