With a Futaba set I would use 60% rates on both ailerons and elevator and 40% expo. This has been my standard default set up for years. If you can put both on one switch to begin with.

One tip. Get someone to stand with you on the first flights and ask them to flip the switch for you if you need it and are having trouble controlling the plane. The number of pilots who have to look at the TX to switch the rates is amazing!