I believe Bryce Mulvey from Dr J's - who produce/market the Air Wolf heads - has a pretty good rep in the States. I do know he asked Edelbrock to recast their heads with lower floors so he could produce the Air Wolf version and they weren't receptive - which is why he went to Pro Comp and asked them to do it.
As for quality, I doubt the Air Wolfs could be any worse than some of the Eddies that have been cast in Mexico. In fact, I'd hazard a guess that quality control would be better for the Air Wolfs by virtue of lower production numbers and inspection.
That said, I have fully ported Eddies and would run Air Wolf heads if I was going to build another stroker, as they have more porting potential and better flow figures out of the box. The reason I like Eddies/Air Wolfs is because everything bolts up to them: LA headers, manifolds and rockers. The Eddies have good, light valves and the springs have a 1.80" installed height, which allows you to use any LS-style beehive spring (which is what I'm running) or any other LS-style double spring (which you'll probably need if you're aiming for 600hp).
Making a "true" 600hp would likely be easier from a set of Air Wolfs than a set of Eddies.
Late-model W5s were better castings than the early ones, and can be identified by the blue core plugs on the ends (earlier castings have bare metal core plugs). They need W2 style rockers and dedicated intake and exhaust manifolds, which is extra expense. A good set of late-model W5s won't be that cheap, either, as they are usually in demand.
The Edelbrock small-block Mopar Victors have been promised for a long time, but have yet to be produced.
Nice VK, by the way - hope you got it for a good price.
