Here's what I found out after talking to Fuel Safe and talking with others in the forum.
http://secure.fuelsafe.net/cgi-bin/fuelsafe/SpecialtyApplications.html
There are 3 models:
SA111A - Pro Cell (16 gal.) $943.40
SA111B - Pro Cell (22 gal.) $1090.75
SA112A - Sportsman cell (16 gal.) $837.40
SA112B - Sportsman Cell (22 gal.) $906.30
The Enduro is a cross polymer replacement bladder that is slightly cheaper but is slightly porous and you may smell gas.
All of them drop in and bolt up once you man handle them into the trunk. Wiring the sending unit can get a bit tricky (more so on the 69-70) but is not difficult. Estimated time for install is 2 hrs for the cell and 4 hours for the wiring.
You will want to purchase the sending unit ($100) and a filler neck ($89) (unless you're planning to open the trunk to fuel your car). With the filler neck installed, it weakens the design purpose of the cell ie the cell is no longer self contained. I believe some folks have opted out of the filler neck for this reason.
The Sportsman is guaranteed for 3 years, the Pro for 10, and the Enduro for 5. If the bladder fails under warranty, then you pull it and send it back to Fuel Safe. Otherwise if it fails you pull the original bladder and and replace it. To replace the bladder, you'll need to unbolt the cell, open it, and take the bladder out.
As to when they will fail, it appears to be anybody's guess. The guy at Fuel Safe said that he just pulled a bladder out of car that had been in since '87 and functioning fine.
He did say that the sponges are more apt to need replacing more frequently but that too is variable. If you are going to store your car longer that 3 months, he said that the tank should be full to prevent drying and cracking of the bladder.
Now you know all I know about fuel cells /forums/images/icons/wink.gif.