The camera probably isn’t as important as how you use it. You can spend a lot of money on a camera body and lenses, to include a macro lens or just buy a middle of the road consumer or prosumer camera. I have had good luck with a couple of decent single lens Fujis, Canons and Nikons. The trick it to learn how to color balance, adjust your f stops to get some depth of field, turn on the macro settings if you want to get real close, otherwise use your software to get close and crop. The most important thing is to get a tripod and use a time delay setting so that, after you focus, it stays in focus. Spend a little on lighting. I use 4 - 5700K CFLs that I bought on amazon and shoot thru a cloth cloud dome. My latest addition is a wireless SD card that allows me to send the picture to my computer without having to remove the card from the camera to see what I got. Some higher end cameras come already wireless capable. You have to experiment and write down what works and doesn’t.
My current setup is to shoot on manual with the F stops in the middle of the range. Let the lights warm up and then color balance on the background of the cloud dome first. If what I am shooting won’t stand up on its own, I either use a support or museum wax to support it. You can remove the support or wax from the image later with software. I use a tripod and a time delay to stop any vibration and the resulting impact on focus. I usually bracket my shots so that I have a couple to chose from. Once they are in the computer, I use software to crop, rotate, adjust the exposure and clean up any unwanted spots.
My software is nothing special. I use a chromebook and a couple of free software apps that serve my purpose just fine. If you are photographing silver, you are in for a real challenge as it is very reflective and you will get hot spots unless you control for them. Again, experiment and write down what works. I know that I spend a lot more time photographing some pieces than it takes for me to make them. Think of it as an extension of your art or at least a learning experience. I hope this helps. Good luck…Rob