I have a friend who put twin (Tractor) turbo's on a 455 Pontiac GTO. The 455 actually came from a firebird. He basically flipped the stock exhaust manifold upside down and put the turbo's directly on them, ran an oil cooling line for the bearings and used water injection to control preignition.
It would "get rubber" @ 60 with 4 people in the car... this thing was a REAL torque monster. Today he is into a little more high-tech Turbo charging on his Harleys. Yes, his Fat Boy is faster than a V-Rod. He also currently holds the land speed record for that class motorcycle. HD has actually come out to to get info on his programing and pictures of his setup.
No, there is no "kits" but don't give up. You will need to do quite a bit of research to get the right turbo's and turbo settings, but holy cow will it ever be a hoot.