I'm doing series one bluebird struts (Which are very similar to 200b or 180b struts as i understand it), with a modified spring perch welded on at the appropriate height to fit lowered 1200 king springs, with r31 discs and calipers which are a bolt on conversion and a 120y boosted master cylinder.
Nice big strong struts, with an easy big disc brake conversion, with lots of spares availability if needed down the track, especially the brakes. Also the advantage of lots of travel and more camber. Mine is only a street ute but i have read of the same conversion being done on race cars with good results. Not sure if there may be bigger brake conversions you can do on the bluey struts, maybe pigdog can help out with the answer to that one, but the r31 upgrade is plenty big for my needs.
Haven't fitted as of yet but hopefully will be shortly if i can get off my arse and do it.
Trav