One pair of full race quality Ohlins R&T forks, in used condition. Fully adjustable, performs much better than any stock forks. Caliper mounts are easy to come by, available for traditional or radial calipers (info available). I bought these for the K4 750 but sold it and no longer require them, they’ve not been installed by myself but have been checked for trueness and function.
They cost me £950, but I’m willing to sell them on for £800 including shipping.