Peek is maybe better than Vesonite, BUT is it better than the recommended product from Vesco Plastics, ie 'Vesconite HiLube' (this is different from the plain old Vesonite Edgar mentioned).
Vesco Plastics themselves recommend HiLube over the older material Vesconite.
However Edgar is spot on wrt the use of PEEK: when I worked in military vehicle suspension PEEK was/is used for the sliding bearings in suspension units, best we found!
There are also some nice German materials from http://www.igus.co.uk particularly http://www.igus.co.uk/iPro/iPro_02_1004_0000_GBen.htm?c=gb&l=en

Regards PJB.

4/4 2.0 Zetec SSL front and rear