You are correct that is not based on the original moulds. The easiest to spot errors are the bottom curve of the chest plate and the fact it's using a plastic wrap around belt. Neither is accurate at all.
RS own a screen used suit and all their kits are based on that.
Denuo Novo took over from a previous vendor Anovos, and as far as I am aware this is the same product. So far Denuo Novo have proven reliable and I had a good experience with their customer service team. Accuracy wise it's pretty good. From what we were told it was scanned from a screen used suit but then cleaned up a little to remove some of the "warts and all". The biggest down side is that some parts a shade on the thin side and replacement parts seem to be patchy on availability and even then you have to buy assemblies.
What ever option you go for I would suggest avoiding the "ready to wear" options. A big part of a storm trooper is how well it fits you and most of that is done during the build, and adjustments are a lot harder with the glues they will use.