I wanted to raise the seat on my '96 205, so I bought these on eBay:
The bottom matched the holes in the floor fine, but the top was too short for the seat slides. I took some aluminum angle and make an extension for the top and it worked out pretty well. The back of the seat is about 5" higher and the front is about 3" higher. I found some stainless steel slides to replace my old slides as well. I also used threaded inserts in the floor and stainless steel allen head screws to hold the brackets down.
I'm sure I look like a geeb with my entire head (6'2") above the windshield, but I can see everything. We had been sitting on two of the square throwable cushions for better visibility.