the water is colder in the spring then the fall....
So with that being said....You could get away with a 3 mm farmer John wet suite with a good splash top.
You can always add another 3 mm wet suite jacket to give your body core a total of 6mm of protection.
The other way would be a dry suite....I don't kayak in conditions that really require the use of a dry suite.....
I shop online at NRS for all my wet suite gear...Great products
Best splash tops would be AQUASKINZ great protection.
Awesome question.....Your thinking safety which is key in kayak fishing.
Kayak1