The 1989 Lowe Crappie boat I'm getting this week has two seats that are moved from the console location to the decks, depending on if you are fishing or driving the boat. I noticed that the seats have a pin that inserts into the boat for moving the seats. Not sure I'm explaining this properly but what I'm hoping to do is get at least one extra seat so the driver's seat at the console doesn't need to be moved back and forth. Hope this makes sense.

So now I'm looking for the extra seat and not sure what to look for. It seams there are many seat available but how do I get the pin arrangement that fits the boat?

Check here for the one pedestal that matches your then go buy a seat.

http://www.attwoodmarine.com/store/category/swivl-eze

Looks like the 3/4" Atwood is just the ticket! From one of the charts it looks like I need a AB style 3/4" pedestal for the console position and all of these are B for the platform seats. It's a great start though and gives me a place to start. Thanks Jig Man!

Do an internet search for boat seats.  Lots of places carry them.  You can spend as little as $40 or as much as $500 for a seat.