Jimmyjeep, I have a 55.1 which is very similar to your 52. I used the front seats of a 2000 Buick LeSabre. It's actually two seats and when the center armrest is raised, it becomes a bench seat. These are power seats, have lumbar support adjustment, a seat warmer if you want to wire it up, center armrest with cupholders and storage, and most importantly for me, has the shoulder straps as part of the seat itself. They fit in perfectly. The trickiest part was fabricating a support frame (out of angle iron and flat plate) because the mount points are a little funky.
I know the purists will argue the removal of the stock bench seat but it is hard to beat the functionality and comfort of this set-up.
