Rear window rubber/roof seal rubbers needed

After a bumpy financial road, I've finally got round to (almost!) having my 89 clipper hood replaced. I need a rear window rubber, as well as roof seals and a bit later, all window seals/rubbers. Can these be got new or only second hand, and what sort of price am I looking at for new or used? Where are the best places for these parts, and by places, I mean prices lol.