That fence is probably pretty uncomfortable Chris.
If you have moved the gas tank out of the cab then a modern set that folds forward will provide access to that new storage area. If your tank is still there and you have plans to leave it then the stock seat is a good choice but if the mounting frame has been removed for your buckets then you will have a challenge getting it mounted.
The modern buick seat is a good choice but it does not fold forward. The Monte Carlo (G-body) bench is a good choice and can be found pretty easily. Another option is the ford ranger bench seat. Any seat that is 55 inches wide can probably be made to work.
A modern seat may sit too low and may require you to fabricate a riser to attach it to the floor. I would also suggest you run a strip of steel under the cab floor to reinforce the seat to cab bolted connection.
