In terms of ships, I think the only canon background info ever released was what was on the 'Official Guide' CDROM and most of which was copied across to the site for the PC game that Sierra were also developing at the time (archived here
.) There is some overlap though as some ships on the site weren't on the CDROM and visa-versa.
IIRC, I think Fiona Avery said in on of the official mags that this stuff essentially came straight from Babylonian Productions (John Copeland I think) so it's as close to reliable as you're going to get. Even the ships that were designed specifically for the game have a fair degree of canonicity to them as I'm pretty sure they were all designed by Tim Earls.