Do you have the arches on already? If not I would buy them and fit them first before deciding the spacers.

On my 4.8iS (168s) I am running 15mm spacer in the front with an e48 offset (US version has no arch extension on front) and 20mm on the back, the 168s have an e30 for the rears. With arches and 168s the 25 and 30 will fit but just note there are a number of variables including the tire width, the e number/offset and the wheel width. They all change when you change the rim/tire combo you suggest.

The 132 IIRC are e48 for the front and e45 for the rears. So changing the wheeels and fitting arches will change the equation a lot.

On my 4.4 (no arch extensions) I just fitted 132s 9s/10s with 255 tires all around, 15mm spacers front and 30mm in the back seems to be about the max without extending beyond the fenders. It is on blocks as the trans is out and the V-pan fix is underway but I will try to snap a photo of it later today and post them for you.

Good luck!