It depends how much you want to carry. If you are mainly 2/3 up then you could do worse than a BE76 with TKS deicing. Only 4 seats, but cruises at 140 IAS and will be OK up to FL90 or FL100.
Beyond that, a non-turbo Seneca will give you six seats but you have to choose between filling them or the tanks.
If you regularly want to fly with 5 or more, then the Aztruck is a good load carrier but attracts Euronav charges because of its weight.