I've been fortunate to have had some of my work mastered at Sterling Sound in NYC. I would talk with your mastering house. You may well end up doing the aformentioned dithering, etc., in Logic, but the mastering house may have more sophisticated conversion programs. They may ask that you send your 48k file as well and see which sounds best. Sometimes even doing an analog transfer sounds better than the "gear-changing" of going from 48k to 44.1k.
Logic Pro X 10.4.0
2.8 ghz Mac Pro Quad core mid-2010 16GB RAM MOTU MTP-AV USB-Midi interface x3
MOTU PCI-424 / 2408 x 2,1224 to Yamaha DM2000 console
UAD Octo pcie card
Yamaha CP33 keyboard controller
Various sound modules connected via midi/MTP-AV's