I have Ohlins on the Blade and Nitron on the track bike. To be honest I can't feel any difference between the 2 shocks, but both are night and day better than standard. It's now the 1 thing I will chose to change on any new bike rather than any fancy parts.
Have you had your standard suspension set up by a professional? It's an incredible jump in standard. If you haven't done it, do it - it improves it significantly. If you still need more then tried and tested Ohlins and K Tech would be worth exploring. My bike is having FGRT 813 forks and a TTX GP shock fitted this week, and I'm really bloody excited about testing it all out after having it set up. REALLY excited.
It's getting set up on 9th of May, might have chance of k tech rear shock at right money. My 600 has wp rear shock and front been reworked, my 600 I use on track but blade only road at min
There's some bitubo front and rear on motoforum just now mate at good money. Seems popular with zx10s
Any after market shock will feel good over OEM stuff. Did U know that a typical price paid by a Jap OEM for their Bikes read shocks is just £35!