I wouldn't hesitate to talk with the guys at Section 8. People have said repeatedly in this thread that they are "sketchy" but no one who has posted here has ever bought a black airsoft gun from them as far as I can tell (if I'm wrong, correct me please). That makes their opinions on the topic worth as much as a pile of cow dung. Also, Section 8 DOES NOT import any black airsoft guns on their own; all of their guns come from a source WITHIN Canada. They ask for payment up front because they don't want people ordering guns left and right and then not paying/picking them up when they arrive. People are right however in saying that they don't carry much in stock; that's more of a cash flow decision though.
If you like the 416, get the 416. I own a CYMA/Sig 556, and yes, its made by CYMA. It's very well made, very solid, and it chrono's about 370 stock with .20gr BBs. The only knock on it is the rear sight, which is a small flip-up affair that is recessed into the top rail. I put a King Arms EO Tech clone on it, and everything works great. So far, 100,000 rounds without a hiccup.
In the end, buy from whomever makes you comfortable, gets you what you want, and makes the process the easiest it can be for you. Good luck!