Hi Major Tom,
I'm in the same boat as you and have asked the same questions before, in fact I've just been in touch with a member on here who actually has one of newimage58's helmets who was very impressed by them. I think I might get one as the price is good, he's in the UK and I haven't the time or the skill to put together one of my own! From what I gather there's doubt as to whether he is known as a 're-caster', ie stealing someone's sculpt and passing it off as his own - although judging by his work in progress photos he seems to sculpt everything from scratch... Until I take the plunge and order one then I can't comment on his service but once I do I'll be sure to post a complete review to clear this up for others who are considering buying one.
Hope that helps
G