Best camera choice to make prints?

Camera choices are hard, Especially when you are working on a budget such as I am. I am a freelance artist who paints and recently decided to pick up a Nikon CoolPix P500 for taking HiRes stills of my work to turn into prints. Along side of my work I have some video projects that would involve me doing a lot of pans and focusing during filming and found that the trick to get manual focusing on this particular camera is really slow. My question is whats the best solution here? Do I look into getting a DSLR with manual focus lens/Detachable lens and drop the video quality to 720p as apposed to 1080p? My budget shouldn't go over $500. I bought the P500 for $320, but would consider going a little higher for what I need. Thanks for your help :)

P.S. Here are some shots I took while working on some unfinished paintings. Criticism welcome :D