I have that exact ELCAN replica now. It's made by Classic Army, and it's a fantastic sight. That's exactly the seller I got mine from, Supply Point 76. And on ebay, it's cheap as hell too. Was like $120 altogether with shipping from Hong Kong. They sell the same CA one at 007 for $300 + shipping.
I like the ELCAN on the rifle. It provides just enough magnification for longer range targets. But for the M4 (to ge that C8A2 look), I think I'd like to get an Eotech replica instead. Better for the shorter range of the M4. And if the CF are using them, then it would be an authentic look.