Most likely they mean nothing. The Commodore 64, 128 and 16 all related to built in RAM. The Plus4 had 4 built in software applications. But that pretty much ends there the numbering system had meaning. The Vic20 was given the number 20 because C= thought 20 was a friendly number. I'd guess (just a guess) with Amiga 1000 they chose a big number to sound impressive, and just worked from there.
