It depends on what the Mac you are getting or already have, what size drive it has, or it may have an NVME SSD M.2 slot.
If you compress the wma to m4a it will use much the same room on a drive, but if you go for the wav option you might need up to 1.5 TB.
If you can't fit the RealTracks and Drums folders on the Mac system drive look for one that is also Mac compatible
Seagate 2TB Expansion Portable HDD External Hard Drive USB3.0 PC PS4 Mac Windows
or smaller if you used compressed
Blueendles HDD External Hard Drive 320GB 500GB 750GB 1TB 2TB USB3.0 Storage PC

You just need to rename these to LibraryM
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