I spent months looking for these and in the end I went with the R&G Crash Protectors.
See, the problem with our bike is that the frame mount on the left hand side is on the other side of the coolant bottle. So to mount the slider to the engine mount (rather than a fairing mount, which is weaker) you need it to pass through the coolant bottle. Both sides require cutting of the fairing.
What makes R&G's unique is that they send you a replacement coolant bottle too, which has been cut to allow the slider bolt to pass through. This makes the slider much stronger since it is a 10mm bolt rather than a 6mm bolt which is used to hold the fairing mounts (aka no-cut).
The down sides are that they are in the UK (although some dealers can get you the parts here) and expensive (approx $150). But R&G is what a bunch of pro teams use (that have our bike) and the site is incredible: Video, flash step by step, written instructions.
Let me know if you want more images or information. There have been a couple posts (three months ago or so) on this specific issue so you should search as well.
I also heavily researched frame sliders for 00-02 ZX6R /05-06 ZZR600 and came to the same conclusion that the R&G ones were the only frame bolt rather than fairing bolt sliders available. It all boils down to what your goals are for frame sliders. Bling factor only? Get fairing bolt sliders, they are least expensive and might lessen fairing damage in a zero mph tipover. Prevent abrasion damage to the engine side cover or main frame spars if you lowside at a trackday or in the twisties? R&G hands down but don't expect them to save the fairings from cracks or rash from a lowside @ >30mph. Check out the pic below I pilfered from another post of a guy that lowsided at 40 mph on his ZZR with R&G sliders. The bolt securing the slider bent back (but did not break) and appears to have saved the left engine cover from getting holed (some scrapes though). The gear shifter, peg, and frame spar escaped damage. But the left side fairing is torn and will need to be replaced. The coolant reservoir with the cutout for the slider also appears to have burst. Did the R&G do the job it was designed for? YES! But the side fairing will be sacrificed in order for it to accomplish that job so you just have to have realistic expectations.
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