As long as the axle sizes match, you will be fine. The triple clamp sizes are the same. If you list what year the 900ss is, then we can see if it will fit the axle. Also, you want one with the 65mm brake caliper spacing so that you don't have to buy an overpriced adapter.
I saw some on ebay from a 1999 900ss. I am looking to get adjustable forks but I would like to keep the handle bars the way they are. I like the riding position and I would rather not goto to clip-ons.
I looked at those on ebay, yes those will bolt right in. You should expect to pay about 300-350 by the time that auction closes. For some reason the fully adjustables from the SS's always go pretty high. I've just started my 748 fork conversion, so i understand wanting to ditch the crappy stockers.