Do not go with a patrol sling!
Three point slings are outdated. There is no need for an extra strap of webbing to get in the way of the mag release, charging handle or get caught on stuff. Also when wearing a sling you want it to go over your strong shoulder and under your weak arm.
The best sling on the market right now is the Vickers Combat Application sling made by Blue Force Gear. It will fit on the C7A2 and C8 as is, but will adapt to any other weapon with adaptors. It's a two point sling made for shooting, not garrison.
Dealers include:
1 RCR Kit shop
3 PPCLI Kit shop
CP Gear
Elwood Epps
The Shooting Edge
Target Sports Center
P&D Enterprise
Plus myself of course