I know USD's are the only fashionable option, but if what you really want is to improve the suspension and maybe if your budget is limited, you could do much worse than fitting a set of 96-97 CBR900 forks. These were the ultimate evolution of sportsbike RWU forks, the top of the tree and as such maybe a better bet performance-wise than heavy, early-generation USD's off an RVF? They have 45mm tubes and, IMHO, the lowers look damn cool for RWU's. You can fit CBR929/954/600RR calipers so you get the best brakes there were before everything went radial, complete with teflon-coated ally pistons. You can still use your nc30/35 front wheel and discs, it fits right in with the CBR axle and spacers (which are longer than nc30 parts).
The whole setup fit with virtually zero effort into my CB-1. The little bit it did take was to fit the headlight and clocks to the yokes but you wouldn't have that on an nc30. The stem fit the existing bearings, was the right length, original top nut, the ignition barrel, steering lock and steering stops all worked 100%. I can take most measurements if anyone is interested in them.
94ish-97 CBR900 forks are similar/same dimensions, but the later forks got better with more adjustability as the years went on. Earlier forks have a speedo drive you'd need to get around, while 98-99 are 10mm wider spaced and want 310mm discs, but you do get an ally bottom yoke.
Excellent performance, much cheaper than USD bits.
Here's a picture which is almost totally irrelevant to your thread, but maybe helps prove a point. I'll be fitting the second disc soon!
