You already have 4 pot double-opposed piston calipers, if you have a '93+ VMax. Going to a 6-pot triple opposed pair of calipers from an FZR1000 from the early '90's is one way. The YZF1000 (R1) early model 'blue' or 'gold spot' double-opposed piston calipers are similar to what you have now. They are a direct bolt-in as they have the 100 mm o.c. spacing of your stock calipers. I think the '85-'92 front caliper spacing is 82 mm o.c.? Someone may wish to correct that if I am off.
Sean's kit for a Hyabusa caliper, or two, is another way to improve things, contact him directly for pricing. These require an adapter bracket for ea. caliper. He sells it as a kit.
More pistons often requires being able to push more brake fluid, meaning, a larger bore master cyl. There are posts about a website where it shows you the ratio you want to be in-between when you count your equipment stats. As-in, "six pistons each 36 mm diameter (for one caliper) and a 5/8" master cylinder." Just an example, those #'s. Plus, recall that you have two calipers, so if each has six pistons, that's twelve total, when using the chart. You're gonna have to do a search for it, I'm too lazy, been working on a big home renovation project which is winding down. Maybe someone else w/more 'moxie' will provide the link for you.
For rotors, the FZR/YZF calipers will use your standard 298 mm discs just fine. Do you get additional benefits from 'wave-cut' edge rotors? Yes, in bench racing, but I doubt many of us ever would subject our brakes to the use required to benefit from 'better' rotors.
Pads? I use HH rated pads in the front and stockers in the rear. Brake lines? Stainless steel lines from Russell, Earl's or equivalent are going to provide a more-firm 'feel,' meaning less expansion under pressure. Wait to buy lines until you get what calipers you want, as the orientation of the brake inlet may require a longer hose/different angle hose end for the banjo bolt.
