I have a Thule Transporter 665C available for rent. Cargo box dimensions: 50.5"L x 24.3"W x 23.5"H or about 13 cf. Carrying capacity is a hefty 150 lbs.
This will fit both a 1.25 and 2 in. class II or higher receiver hitch. It includes locks, key, and 4-pin pre-wired taillights.