A similar question was asked ths morning on the Vettenet.
If you're using an oil cooler up in front of the radiator, the best way to plumb that is with braided, stainless-steel covered hoses with AN-type compression fittings. For a BB, you'd probably want AN-10 lines and fittings. I've used nothing but Aeroquip in every cooler installation I've ever done, mainly because it's a high-quality product with which I've never had any trouble with leaks. On V8s, I've used -10 lines and on V6es, I've used -12 lines.
I would certainly not use "rubber hoses" as they're not reliable for engine oil coolers and I wouldn't use copper. If you want hard lines, use either aluminum or steel.
Where the hoses run close to header tubes, use a heat-resistant covering. Aeroquip makes such a product. Presumably, there are other companies that do, as well.