On the subject of grey imports, I purchased a rather expensive camera and lens from
E-Infinty, as I decided the saving was enough to justify the risk, and the items do come with warranties, although one does have to wonder how effective these might be. The delivery took a while, but the camera has served faultlessly for nearly five years now!
You may find that stocks of new DSLRs can be quite patchy now, as the industry has very much moved on to mirrorless cameras. There are plenty of articles online about the merits of both types, but I think for your needs you wouldn't see any particular difference either way.
I can understand wanting to have a new camera, but I wouldn't rule out purchasing used.
MPB have a massive range of used equipment, and you could get a better camera and lens, but still have money left over from the price of a new 2000D. I've bought a few things from them with no hassle at all, and I've also heard good things about their warranty and returns procedure.
The most important thing though, is to learn about the different settings, and how these affect the images you take. It can be a steep learning curve, but it will pay off when you instinctively know the best way to set your camera for the photos you want. Probably the most specific point for bus photography is the balance between capturing a sharp photo, but also capturing the LED destination screen, as these flicker at a rate so fast that it's invisible to the human eye, but can result in partial text or no text being captured by the camera, something you may have noticed on your compact camera. As an example, for a vehicle moving at 30mph, I would set a shutter speed of 1/500, which should freeze the motion, but gives a reasonable chance of getting a full destination screen. A faster speed of, say, 1/800, would mean less risk of blur, but may not capture the destination screen. A slower speed of 1/250 would likely cause blur on a moving bus unless it's at slow speed, but if the vehicle is stationary at a stop then you can drop the shutter speed down, but if it goes too low then you may get blur caused by the camera shaking. Taking as many frames as possible obviously helps to increase your chances!