For turbo stuff check the tech section there is an article on turbocharging that has been pointed out quite a few times now.

EFi is the best setup but also the most expensive. Basically the computer runs t he whole show. Injectors, throttlebody etc. The advantages of efi is you can use an intercooler.

1 turbo is easier to setup than 2 turbos and with the new technology available with ball bearing turbos there is no need to worry about lag.

Craig