The RVF front fork conversion is the most common. Infact Jha offer a kit, or alternatively ask the boys at Tyga. They may be able to send you over an RVF yoke pre assembled with an NSR stem.
Basically you have to purchase a set of RVF forks and yokes. Grind off the weld that holds in the stem, press it out....press in the NSR one, weld it up again and hey presto you slip the whole lot back into your NSR frame and have one trick lookin' scoot.
Watch out for the RVF forks hitting the radiator. Not sure how you cure this.
I've run with 140, 150 and 160 section tyres and quite honestly didn't feel the difference. Yikes I must be an insensitive git! I rode a Ducati at my last track day. Did about three or four sessions on it and told Scott V that it was a little 'twitchy' on the fast sweepers. He did one lap and pronounced it unridable!
Get on em an ride em.......that's my motto.....well if I can find the time between work, the kids and an ex wife!