A basic 3 jaw puller won't get the job done. It has to be an A/C puller. It threads into the outer plate, then has a threaded rod push on the shaft to remove the outer plate. Once it is removed, then you remove the C-clip and use the 3 jaw pullers to pull the pulley off it.
As for pulleys, I haven't found a GM one that isn't interchangeable so far. I used an 88 4cyl serpentine pulley on an 86 V6 compressor and a mid 90's 3.1 pulley on an 87 V6 compressor. The 3.1's were all serpentine and from 88/89 the 2.5's were as well.
I Had a brand new (just been sitting in the box for a year) 2.5 AC compressor. I DID swap the pulley, "Drilled" the mounting holes out, and bolted it right up to my 3800. Lines up perfect, Fiero AC Hoses bolt right up. For free, I can't argue with it ! Just had to change the "Pigtail" on the Clutch Plug.