Since I have used most of the set ups talked about in this thread I will try to share some pros and cons of each.
Stock KYB forks: Well made. Similar to Ohlins in design. Lightest OEM fork available today on a liter bike. 20 mm piston with 10 mm aluminum damping rod. Orifice damping [small hole pistons]. .925 kg/mm springs. Too much high speed damping on compression and rebound. Bushings are smaller than Ohlins which can result in stiction under hard braking.
LE: Have used his set up in the past on some Honda forks but not the ZX10R. He modifies the stock 20 mm pistons and installs his shim stack. Better than stock but expensive for what you get, but if you are on the west coast he will help you set up your bike at the track if he does your fork work. Price on KYB forks unknown.
Ohlins 20 mm Supersport piston kit: Orifice damping pistons with slightly larger ports than the stock KYB. One shim stack supplied for all forks. You need someone with experience on the ZX10R KYB forks to install them and get the shim stack correct for your weight and riding style. Better feed back than stock but still using 20 mm pistons and 10 mm rod. $500 to $800 depending on what's replaced, springs, seals, etc.
High flow 20 mm pistons. RaceTech [compression only], Traxxion, Penske, K-Tech: The key here is set up knowledge of the installer. Damping is controlled by the shim stack only on high flow pistons. Ohlins and Penske use high flow pistons in there shocks. Traxxion uses a digressive high flow compression piston in there fork kits. Better feed back than stock but different than Orifice damped pistons. Still using 20 mm pistons and 10 mm rod. $500 to $800 depending on what's replaced, springs, seals, etc.
Ohlins 25 mm Supersport cartridge kit: 25 mm pistons with a 12 mm rod. Orifice compression piston, high flow rebound piston. Rod size makes a difference on compression damping. The benefit from the larger piston size is claimed to be more surface area for the oil to push against which results in less cavitation and heating of the fork oil. When the fork oil cavitates your high speed damping is reduced a bunch. All of these cartridges come with .90 springs from Ohlins. Unless your 150 pounds you will need to buy replacement springs for another $120. Every set of Ohlins cartridges I have had, even though they are bike specific, have the wrong damping set up. The high speed rebound is so stiff from Ohlins you can not ride the bike, They need to be revalved and resprung right out of the box. I drill the compression pistons out to 2 mm from 1.5. Basically the same internals as the 2004 up R & T forks but valved different. Much better than stock, when revalved, but expensive. $1700 plus and you need someone who knows what they are doing to install them. Plus you need Ohlins fork oil which is $28 liter. Unless you are racing in Superstock or Supersport which require stock fork externals, you are better off spending a little extra for R&T forks.
Ohlins R&T forks: 25 mm pistons with a 12 mm rod. Orifice compression piston, high flow rebound piston.
Basically the same as the Ohlins supersport cartridges with a different shim stack. .95 kg/mm springs. Very good set up out of the box. The least stiction of any mass produced fork. I drill the compression piston to 2 mm and change the shim stack. Personal preference.
$2200 to $2500.
Traxxion AK-20 cartridges: 20 mm pistons, 12.5 mm rod. High flow 20 mm pistons, digressive compression. This is a similar set up to the works Showa forks used in 2000 and 2001 on factory superbikes. Custom for each fork. Uses a check valve in the rebound circuit to eliminate cross talk between the compression and rebound circuit. Has a spring buffer similar to the Ohlins R&T forks. Floating damping rod bushing for less stiction. Includes calibrated replacement compression needles. Feedback is similar to a gas charged Ohlins superbike fork. Different feel than any of the other set ups listed here. $1000 plus installation costs.
If you are just riding on the street and doing a few track days I would replace the tires first. The rear shock next and the forks last. The OEM Dunlop's suck on the track. The stock shock is much worse than the forks. Once you replace the shock the forks will not feel as good as the rear. If you are a serious track day junkie or racer then the forks need to be up to your riding capabilities and what you can afford.
Make sure who ever does your suspension work, forks or shock, has knowledge of the ZX10R. It is a difficult bike to set up properly. I would ask the shop doing your suspension mods if the stock forks are reworked will they swap out the springs or revalve the forks if the set up is not to you expectations at no additional charge. Same question for swapping a shock spring if the spring is wrong for your weight and riding style.
Your results may vary.