Keeping an old Suntour drivetrain rolling
I commute on an old (1989ish) Bianchi Tangent cyclocross bike with Suntour XC Comp components. I love it, but that's not the point of the thread. Recently one of the sprockets on the rear wore out and I had to replace it. Turns out, the Suntour cassettes have different splines than anything that's currently made and a new old stock cassette is at least $80 on ebay! I also can't change to a Shimano hub/cassette without giving up index shifting, since the sprocket spacing is different.
My question is: how can I keep the bike rolling with mimimal hassle and expense? My thought so far:
1x Shimano 7-speed hub
7x 2mm (5 or 6 speed) Shimano sprockets in appropriate sizes
3x 2.8 mm spacers (I think campy 9-speed uses this size so it should be available)
3x 3.0 mm spacers (Shimano/SRAM 8-speed uses this size)
The shifting is 7-speed Accushift Plus. From what I've been reading, this should create a rear wheel from easily available parts that is compatible with my index shifting. Source: http://sheldonbrown.com/cribsheet-spacing.html
Am I missing something? Will this work? Is there a better alternative?