I've got a Nishiki Colorado mountain bike with a suspension fork...the fork doesn't hold air, and one of the canti studs has been broken off into the mount, with no way of getting it out (it dulled and then blued a diamond tipped drill bit). As a result, I'm looking to go with a new fork, that is preferably cheaper. I'm looking right now at the Tange cromoly forks (~$40), and the cheaper, hi-ten Sun forks (~$20). How much fudge factor can you assume when screwing down the threaded headset? Can it be a little short and still work? My biggest concern is getting one that is way too long. There's no way to put spacers on it to allow it to be screwed down, is there? What would you guys recommend? I don't have the bike with me right now, but it's a 21" frame. Not sure of the head length, but the forks that I've found don't really come in many different steer tube lengths.

Also, 1" is what I'd need, right? It's got a standard quill stem, so I'm doubting 1-1/8"...