I've used PVL on my four stroke racers very successfully - best I've had are Interspan (bulky) and rex Caunt who works out of the units at Mallory Park. Rex's units are top class and uncommon to PVL self generators, he usually keys the rotor for the bike so there's very little setup issue. Electrex have a very good reputation but I haven't used them personally. They seem to use fairly standard PVL parts.
I've currently got a Boyer powerbox to generate sparks on my 750 - uses a stator/rotor off a CB350 in my case but have changed to the Dyna 2000 ignition to get better control over what's happening. Nearly got that all wired in so can't report back yet but we're nearly there!
If money is not so important I'd go wih Rex every time, his service is impeccable and his products are extremely good...www.rexcauntracing.com