SHORT ANSWER
Go with the new car if you've NEVER bought a used car in China.
LONG ANSWER
The JINBEI is significantly more popular as a work van, so if/when things go wrong, as they usually do, there's a JINBEI repair shop almost everywhere.
That being said - it's also subject to more abusive driving (have you ever seen JINBEI drivers - they're Formula 1 wannabes). They overload their vehicles (so you should expect the shock absorbers to be on the verge of collapse) and the engine and transmission systems are bound to be near death.
Buying a vehicle new in theory should theoretically alleviate the plethora of things that can and will go wrong with heavily abused used vans - brakes, brake fluid lines leaking, transmission and transmission fluid problems, radiator issues, fuel issues (like did they replace the fuel filter), oil system issues, engine issues, tires, lubrication points, stupid electrical problems, water damage, etc etc ad infinitum.
Again, if you've zero experience buying a used car in China - best to just avoid the issue as the used car dealer is almost certain to promote and foist his lemons onto the unsuspecting foreigner. You'll spend many a day kicking and cussing your vehicle and everything else in sight.
IF you elect to go with the new car - the above problems are also possible to arise - but at a lower incidence and probability - but this is all just statistics as the reliability of new domestic cars also requires research into the Chinese vehicle boards.
You'll need to identify all of the new car dealers & service centers for all of your major and perhaps even minor destinations - if WULING isn't there - you may have problems if/when your vehicle breaks down.
Finally - if you're planning on driving into Beijing - be advised you need PERMISSION to enter Beijing if your car carries non-Beijing plates. You should take care of that at your local Department of Motor Vehicles (DMV)...dunno the Chinese name...but you'll experience that when you buy your new vehicle.
Finally - beware of car thieves - these two brands are high theft items. I'd probably add an ignition kill switch in the glove box or some other super stealthy location (like the cigarette lighter)...but I'm paranoid (for good reason).