When you look at the 2 chassis the Anderson is much more stiff and heavy duty looking. The PVP is a flexi flyer so to speak. I own an Anderson but have helped a friend build a PVP. I have driven it too. Both get the job done, it’s just 2 different thought processes in achieving it.
As for parts both Anderson and Ian at Viper are in England and ship pretty quickly. PVP parts come from Denmark and although I have never ordered anything I have been told that it’s nowhere near as easy as getting Anderson parts (bank transfers and such). Larry Dobbs can tell you about that.
On the west coast it seems there are a few more Andersons than PVP’s around. Both can be fast in the right hands.
Starting is not that big of a deal. You can push it, you can modify the starter shaft so it fits in the seat. Some guys even start it with a big nut on the end of the axle. All will get the job done.