your primary reg should have your long hose (7'), which is run off of the right post, down the right side, around your neck, with the excess under the canister light, or in your case, the excess tucked in your right side waist harness. Your backup reg should be on a short hose with a necklace, hanging under your chin. That way, you don't have any hose to bungee. I would start from the get go, wearing the sling bottle on the left side. If you get used to wearing it there from the start, when you eventually use 2 deco bottles, it will be a lot easier to add another to the same side. You'll find that with a little practice it'll seem like second nature. I use 2 deco bottles, both on the left side (O2 on the inside)and have found that I have no problem. As previously stated, switching to the wrong gas is the biggest killer of deco divers and if you start by carrying the bottles on the left side, you won't have to relearn bad(and potentially deadly) habits. I have a D ring on the right side of my backplate, that I attach my reel to. right behind the canister light. It's out of then way, but easy to get to when I need it. Good luck to you and Dive Safe!