The datacard stats are also in the Force Manager program, but that is as close to a database as I am aware. If there is an active database I would also be thrilled to know about it.
For the vehicle (and I'm assuming CAV) images, the ones that don't have color data cards generally don't have known images, BUT: CAVBoss has a lot of art and modelling done for unreleased things. He wanted to transition to monthly releases more than a year ago, and was just able in August due to the complications in getting Dualcast started. Some of those were modelled on stream by Chris Lewis and are probably on youtube. If there is something that you are particularly curious about, CAVBoss has always been very approachable, you could send him a message asking if it has art.
One other thing to note: The faction model list sheets will tell you if a model is a variant of another. This can be handy if what you're looking for is something like the Pilum, which we know is a Javelin with medium guns (and then find that the Kestral has medium guns that visually work with the chasis and are of the same faction).