I have an old set of StM pants and Jacket. I am not sure how the design may have changed since this is a couple of years old but I was only moderately happy with it. The vecro is fairly cheap and the fit is a bit odd. The pants were very tight around the lower leg as well. The material itself is fairly robust and resistant to pilling and holds up to repeated washings.
As for a US vendor, maybe try Escrime Line International out of CA. IIRC they are somehow affiliated with the musketeers club down that way. Check out
www.shopeli.com if you want. As far as I know they are the only stateside club that stocks any StM kit other than blades.