Does anyone recommend this combo for street and occasional track use? How long do renthals last, especially the rear sprocket on a vfr?

The tsubaki chains alpha/sigma chains are very good quality and should last for over 10k mls on a 400cc bike if looked after, the rear alloy sprockets dont last as long as a oe steel ones on large capacity bikes, front renthal sprockets are hardened steel and seem to wear ok.
I would keep with the standard 525 pitch as this will last longer than a 520 race conversion.