Going with a dual or quad carb setup is an easier mechanical conversion. The kits are readily available and are about 75% bolt-on. Base tuning of this type of setup is fairly easily and the chance of messing up the engine are relatively low. But you will not make as much power as an ITB (individual throttle body) setup or a turbo setup. Should make as much or even a little more power as a s/c setup.
My choice would be to go ITB. The kits are about the same price as a carb setup, but the tuning will be a major investment. If you know what you were doing, had some good tuning and engine management software, a wide band o2, and the ability to make or have somebody make custom hardware, you could build you own kit. The basis of which would be 4 motorcycle TB's. An ITB setup will make more power than a carb setup.
