More importantly, if it is " Dock High", does it have a icc bumper for the dock lock to lock to? Are you going to stay local? Is the box floor forklift rated??., is there a legal sleeper? Sleeping in the front seat won't cut it in a day cab, and you will need to show proof of motel receipts if dot'd at a scale house. There are so many variables..do you, or are you, able to secure the proper insurance requirements? Do you have an active ifta account? If you have a roadside repair/ flat tire, do you have an account with Bridgestone/Firestone, Goodyear? If you are going to go out on your own, these things will be needed as a true and proper owner operator.. these are things that a good company to lease on to may provide for their owner operators....The list goes on and on...
Not trying to rain on your parade, but better to know and be prepared than to find out the hard way. Honestly? I'd lease onto a good carrier that is willing to accept your truck.