£1800 should easily see throttle bodies bought and fitted. With that you're lookin at around 165bhp and if I remember correctly a slightly higher torque figure.

If you don't intend to use the power all the time, perhaps NOS is a better and cheaper option? I'm not sure but a 25 shot should be safe with the standard internals, maybe 50? Cost of that fitted is probably £600-800?ousing

Pretty sure that Turbo/Supercharging will cost more.