Determining if it's high output or not is pretty easy. The badge is the easiest way. But as Peva said, 3.2's (all of them from I seen) have the high output MTV/SRV equipped.
I attached a picture of what a High Output 3.X Intake has for illustrative purposes. If you compare it to yours (which I assume is not High Output) you'll see the difference.
As far as seats go, just go to the yard and yank a set, bring a set of sockets, 10,12,13,14,15,16,18 MM. Pop off the lower half by yanking up and then remove the bolts for the seat buckles and any others you see there, then pull the bottom out and lift up. It will be a work out muscling it out, and it may just pop out easy. Their all different.
As far as PCM's go. You want a 300M SPECIAL PCM. Need to match it to your year. 98-01 to 02-04. Has to be within the year bracket as your car, since in 02-04 the ECU and TCM were married to be the "PCM". Aim for a 2002 model year I guess, seems everyone says it's the cats ass... =/