P11 Dual Exhaust Project

I am wondering as to whether it is possible to set up a dual exhaust on a 2000 G20. I want to use either APEXi or HKS mufflers. Im sure there is a way, but I am unsure as how to go about doing so. Also what quality companies are there that produce custom piping for such a job. If anyone can give me some info on this, it would be greatly appreciated. Thanks