Okay as soon as I post this I'll find the anwser right under my nose!

Is there a discussion regarding the pros & cons of armour makers/finishers, suppliers of kit, etc?

It's more of a discussion of materials used than particular makers. Some people prefer fiberglass, some resin, some vac formed abs or boltron plastic. Fiberglass is strong but can be brittle and crack, resin is strong but can be brittle in thin coats and can get thick and heavy, abs is strong, flexible, and durable but you lose some detail of the parts because of the thickness of the material and they way vac forming works.