You probably can't use the 165 because although the headset will take up about 37 - 45 mm (stack height) the top race must be able to screw down sufficiently. There's no way we can tell you for sure - why don't you just measure the amount of threads used on your current setup? If you have a good 5mm of leeway with the 165 then it technically should work.
That being said, the 145 is a much better fit - depending on the headset you choose you may not need to cut the fork at all. It is not a good idea to raise the fork that much unless you have determined that will work properly for you as far as fit. It's best to adjust fit horizontally before going higher in front, as that changes weight distribution more than it does reach.
Last edited by cny-bikeman; 07-10-12 at 07:14 AM.