Have a little experience with this stuff.
An L1/2/3 ZXR750 is an awesome road bike. However to make a competitive productions racer from it will require a lot more work and money. They weigh a lot, and the motor is actually not that good in standard trim. They need heaps of set up $$$$ to make em go really quick. Triple clamps to get em to steer, the forks are low low rent jobbies and suffer from horrible hydraulic lock on high speed compression. Most guys junked em and put Ohlins or WP forks in them. They require a different link and rear end set up too. Spares are getting hard to find too. A mate of mine doesn't race his any more due to spare parts being thin on the ground and almost as exxie as new now.
Whereas the 95 ZX6R F1, is pretty simple to get going. Fork springs and a revalve, new rear shock, braided lines pipe jet kit go racing. Parts are easier to get and there are still lots of spares out there left over from old racers. (Get in now before new era riders snaffle all the good bits up.) They get around a race track (rider equality assumed) quicker than a proddy ZXR750 does. Yeah sure a full blown ZXR750 SBK will hose it, but then you're talking engine rebuilds a few times a season, or at the least one, but with SBK spec motors, they are not cheap to build. A ZX6 engine can be redone with stock parts on your dining room table. (

Yeah I did that when i was racing-I didn't have a work bench

) I just had a top and bottom end done on the racer, and it included some new parts like a starter clutch and some gearbox internals, as well as bearings, rods, pistons, rings, guides and seals, and a few other things for under 2K. A SBK spec motor will be 5K minimum for that, perhaps more.
Hope this helps.
