Hinges: rumor is you can use 240sx hinges for the uppers. The lower hinges you need to go to a junkyard if you want to get cheaper ones, but make sure THOSE aren't in need of replacing as well. Courtesy Nissan has a decent price on new ones, but decent is a relative term, probably $100 for a set.
The weather stripping I'm not sure. You'd probably have to go to a dealer (Courtesy again perhaps) or rig something. I have the same weather stripping problem in one of my B13's, I will get around to fixing it soon.