My battery has been relocated to the front, using a Norm's Fiberglass box. Very similar to Archie's. Although Archie's is probably "prettier".
The + lead - probably an Olds Aurora, or similar cable - is run down the center of the car, on the right side of the gas tank. It is routed over the bracket that supports the tank. It is protected by heater hose anywhere that it comes near anything metal, and also at the places where it is fastened to the car. It is run straight to the starter, and a smaller wire is run from the starter, up to the terminal strip under C500. (Near where the battery normally sits.) That wire is also protected by rubber hose. Fuel line, I think.
I have two grounds connected to the engine. Both are normal size battery cable. One from the rear head to the shock tower. The other from the stud on the bell housing, to the left hinge box.
The ground from the battery - also a normal battery cable - is connected to one of the studs that holds the power brake booster. There is a knife switch in the ground cable, at the battery.
I use a Duracell AGM battery. I used to have an Optima Yellow Top, until it died. The Duracell is about half the size and half the weight of the Optima.
I have had this setup for over five years, and it has caused zero trouble. (Well... other than the Optima dying. But it was labeled "BLEM", so who knows what might have been going on with it.)
If the car is going to be parked for an extended period, I open the knife switch.