TAS 661. .For the range you are looking for 500-600 NM, I'd guess you would need an 8-9 seat aircraft. A B58 is a luverly ship to fly, but you won't get the range you want, without being a 2 pax aircraft. I have never operated a shrike, but I know those that have, and they rave about them. If you could find one, it could probably do what you want. Failing that, you are in PA31/C402 territory.