Pretty much any of the D1000 (3000, 5000, or 7000) series cameras would work. The newer, the better. The biggest advantage to a newer ones is Nikon has some newer lenses (AF-P) that only work with the newer cameras, mostly DX500 and higher. The great thing about the AF-P lenses is they tend to be cheaper than the older ones (when new). But any of them with an 18-55 would fit the bill.
As for flash, it depends on how easy you want the flash to be. Some of the newer ones will have auto flash exposure modes. The older ones will need to have the flash power and camera exposure manually adjusted. Since you're shooting static scenes, that won't be hard to do, but might be a bit time consuming. The older flashes, especially ones made for film cameras, would be significantly cheaper. That would allow you to afford more flashes and probably some flash modifiers, which is what's most important for a professional look. You want smooth, diffused light, not harsh direct light. Something like an SB-26 would be great. Also, you'll probably want a remote flash trigger system so that you can get the flash off the camera, and trigger multiple flashes at once. You'll also need a good camera tripod and some stands for your lights.
You might even consider using shop lights, which would be easier to set up than flashes because you can actually see what you're doing without having to check the back of the camera. Just make sure to get daylight balanced lights, so you don't get one color of light coming from the windows and another coming from the flash.
Skill is more important than gear. So what you'll want to do is find as much as you can online about how to light a room and how to frame a shot. A good photographer will take an exponentially better photo with poor gear than a poor photographer will with the best gear.