the second option is for external gate, your turbosmart actuator is a IWG75? they take same springs as 38 ultragate etc
turbosmart does a range of high psi gates now, come standard at 35 & 40 psi
as above, anything bigger than the stock should be tuned, otherwise there's a good chance you'll blow the motor before the tuned cars in the unopened 300kw club (even though you have much less kws)
Voncina- 7 psi on this turbo all good still?
they work in combination, inner, mid & outer, if it's 5 psi it's probably an inner so could get a 7psi mid + 7psi outer for 19psi, check the spring colour that's in it then order from the spring combo chart
as above, r33 will usually have the half round type cas drive, the last of the s2s that take the neo style cas has a rectangle with a dip in the middle
it'll bolt up to the auto, will run off the 33 loom & ecu if you change plugs, cas wiring & maybe coil wiring, assuming the 33 is a 25de not a 20e
changing loom & ecu would be better