First of all you should maintence your Y8 before you throw the turbo on. Depending on what you did and didn't already yet you'll need to replace timingbelt/tensioner, colder spark plugs, and anything else motor related that needs maintence work. Also get a compression test...make sure your motor is in good shape to run the turbo or you'll have problems down the line.
what kind of turbo is it? It looks like your getting a almost complete setup. From what you stated you'll need to run a oil line to the oil pan, piping, other gauges if your missing them, aftermarket injectors, ecu (i recommend CROME only) and a aftermarket fuel pump. Upgrading to a stage 1 or 2 act/exedy clutch would be alot better. AFter the install get a good tune and you should be good to go.