I have used the below for enclosed transport along the East Coast. Not the cheapest, but reliable. This may well be an area of 'you get what you pay for", but it also depends on the valuecondition of the car.
Lana
Exotic Car Transport, Inc.
880 C Maguire Rd
Ocoee, Fl 34761
800-766-8797 ext 103
lanah@exoticcartransport.com