I'm puzzled as to why another option hasn't possible been mentioned, or considered. I don't own a PA (but hopefully will some day) and I've gathered vast amounts of intel of how to rig, mods to make, etc.; most of them from this forum. The solution to moving the seat seems to move it an inch back by drilling extra holes; and then I think, there was a comment somewhere of having a swivel seat as well. Then, I remember this thread:
http://www.hobiecat.com/forums/viewtopic.php?f=78&t=33246and I look at the picture of where the bracket is bolted on, and think, geez, you could move the seat a lot more if you wanted to. It would mean the addition of some bolts to mount the pedestal, but why not have a smaller/lower mount, that swivels, and you could attach it to your seat and the boat, and possibly move the seat back another couple of inches....Wait a minute....what's this?
http://www.basspro.com/Wise-Boat-Seat-Swivel/product/16129/-635834Something like this could keep your CG (Center of Gravity) lower, allow you to rotate and reach items in the rear while maintaining a center position in the boat, and, move the seat, either by making new holes and moving it back, or, just moving it up an inch instead of back an inch which could resolved the issue.
I do remember in the previously afformentioned thread, that moving the seat could cause strain on the mounts and possibly damage the boat, but, I suppose that is one of the risks you take when making alterations.