the variable inlet would be your only real issue, the actual mounting of the manifold wont be an issue as the 1.8/2.0 mount the same as the 170 (people use the inner inlet for TB conversions) but the main bulk of the power the 170 has is in the vvt system so unless your doing a full conversion it might not be worth doing? iirc the 170 is only actually 140bhp before the vvt kicks in and the majority of that 140 was in the head..

im sure there will be people more clued up than me that will help but have you not thought of using the inlet as a start for a TB conversion?