It is a catch 22 but they will refuse the 818 because it is not a FULL air brake system. The manual clearly states that 3 essential requirements must be met in GA to obtain CDL with air brake endorsements (and in GA it is an actual endorsement).
Air Brake Check (Air Brake Equipped Vehicles
Only)
Failure to perform all three components of the air
brake check correctly will result in an automatic
failure of the vehicle inspection test. Air brake
safety devices vary. However, this procedure is
designed to see that any safety device operates
correctly as air pressure drops from normal to a
low air condition. For safety purposes, you will use
wheel chocks during the air brake check. The
proper procedures for inspecting the air brake
system are as follows:
Shut off the engine, chock your wheels, if
necessary, release the tractor protection
valve and parking brake (push in), fully
apply the foot brake and hold it for one
minute. Check the air gauge to see if the
air pressure drops more than three pounds
in one minute (single vehicle) or four pounds in one minute (combination
vehicle).
Begin fanning off the air pressure by
rapidly applying and releasing the foot
brake. Low air warning devices (buzzer,
light, flag) should activate before air
pressure drops below 60 psi.
Continue to fan off the air pressure. At
approximately 40 psi on a tractor-trailer
combination vehicle, the tractor protection
valve and parking brake valve should close
(pop out). On other combination vehicle
types and single vehicle types, the parking
brake valve should close (pop out).
Step 3 cannot be done because the vehicle is not equipped and therefore disqualifies your ability to earn the endorsement.
As far as CMV, if it's for personal use you can get the regular class A like myself and some others. This license does not require ANY endorsements. I can drive a double, tanker, air brakes, whatever as long as it's not for profit/hire (crazy). But the test questions still come from the CDL manual and includes air brake questions. Basically, you need to know everything you would for the CDL exams. Just no road test. If the vehicle meets the weight limits of a CMV it doesn't matter how it will be used, it will still require some type of special license.