I am looking at selling my 4900 and getting a P5000, and I noticed that the two printers are identical in physical size and appearance (not really surprising if all that Epson did was change the inks and the print head). So it looks like I can keep my dust cover, spare maintenance tanks, and my cart. The cart is especially important because when I bought my 4900, I had a heck of a time finding something to put the beast on! I was remiss at the time in not posting my solution, something I will correct now that I am again looking at a new printer.
My solution was to get a Uline utility cart, #H-3325https://www.uline.ca/BL_1879/Uline-Utility-Carts-with-Flat-Shelf
The fit is just perfect, there is ample storage underneath for papers, and the handle + wheels allows me to maneuver it however / wherever I need to.