On my AR I have 2 sections of rail I need to buy for 2 attachments. I have a Cobra Tactical foregrip, and will want a left side(to activate with off hand) light mount also. So I need 2 sections of rail for that...Anyone know what length I need to get?

I was kinda assuming 5 or 7 was needed just didnt want to get too short a one...and do I want a scout mount light mount or just 2 "regular" mounts.