If you could find a cheap 3.2 (good luck), the swap is not difficult. If your 3.0 is in good shape, you could get some of the money back for it. I personally would keep the 3.0 ECU and harness (Mark B., this works doesn't it?).
Before going down this road, I would seriously consider spending the money on other modifications. Displacement makes everything better, but if you just need a few more ponies, there are easier ways to get there.
If your motor is really screwed up (fatigued block or badly threw a rod), looking for a 3.2 is a good plan, but otherwise, I'm not sure it makes sense. I pulled my 3.0 and spent a fair amount of money going through it, so I first looked around for a 3.2 block, but could not find one. In the end, I'm not sure it made any difference.
Just my .02.