Well.... You will want a bar sensor. 2 bar is probably enough if you don't plan on boosting over 10psi. So the first question is, does the 1.8 already have a bar sensor in the intake manifold?
If not, the post IC charge pipe is an acceptable location.
The next question is, can the 1.8 ECU be tuned to read boost from a bar sensor?
I suppose MAF reading alone could be adequate, and you could run a mechanical boost gauge. But I imagine a tune that can use feedback from a bar sensor would be preferable.
I don't have any experience when it comes to adding boost to a N/A engine. But these are the questions that pop into my mind. I have a buddy that runs a push-through turbo set-up on a non-computer carb with great success, but fuel injection need feedback to determine how much fuel to apply.