Many of us are very pleased with the Radix supercharger. The Livernois turbo kit does indeed look nice. The vortech and ati superchargers make nice peak power, but they don't quite have that low end torque a heavy truck needs IMO.

Wait on the custom tune until you have all your mods planned out, otherwise you'll be getting an updated tune everytime you make a change. If you are serious about making power with your new truck, you should consider doing your own tuning. EFILive and HP tuners make quality tuning products you can use yourself.