I have experience with epson and canon machines from my uni days, as well as my own ipf8400. I don't have experience with the HP fine art printers. In my experience, Epson printers are a pain in the ass. Constant nozzle checks and cleanings. I know the latest 44" printer has all sorts of issues. I've used both my ipf8400 and the latest pro-2100, both very good machines. 3rd party tests have shown that the Lucia-ex(ipf8400 and related machines) has better light-fastness and green gamut than lucia-pro inkset(pro-4100, 2100, 1000, etc). However, the ipf8400 and related printers are quickly approaching end of life. I also doubt you could find one new anymore.
The pro-4100 would be my recommendation. The software suite is key to getting the best results. Custom media types, calibration, canon print plugin instead of windows print driver, etc.
