My Air Cooled knowledge is pretty limited. However, anything is possible right? Typically the hurdle to overcome is the actual seat base/rails. I have no idea if there is anything that can be just swapped in, but you could always use stock seat rails and find a way to graft them to a more modern seat base.
There are a few air heads on here a lot more knowledgeable than I am so hopefully they will chime in and can provide some details.
Hopefully this link might help you out in your quest for knowledge:
http://www.thesamba.com/vw/forum/viewforum.php?f=3The Samba is a great site for AC VW owners. I'm not trying to turn you away from this site, but the collective AC knowledge here might not get you far.
