I've been doing large format printing for about 8 years now, I'm on my second 54" printer. You can have prints done on canvas, but even a 60" printer won't give you a five foot stretched canvas. The printers don't go edge to edge and you need some extra for the frame. I would figure to subtract about 4 inches from the printer get the actual frame size. There are also liquid laminates you can paint , spray or roll for a different finish and UV protection. You can have prints done in either solvent or water based inks also, the new eco-solvents are probably your best bet now. $10.00 (US) or less, a square foot, would be the price range.

 The other issue I think you should consider is what you will be able to get pricewise for your efforts. People will readily pay much more for an actual painting than a printed 3D render. It's not even close. I can do an average size painting ( 3 feet ) in one day and get $600 to $1,000 for it, but people will offer as low as $30.00 for a print of a render. If you have the ambition to paint, I wouldn't give that up for doing just renders. If you want to make money and utilize 3D to help with composing your paintings that can be useful tool. Personally, I think the best way to make money is to use 3D to design your paintings, then paint the finished product. Then if you want to sell prints, have them made from the actual painting. You will find customers place more value on them than prints of 3D renders. Some may argue that a render is worth as much as painting, but the marketplace doesn't agree at this time. It's also not necesssary to divulge your methods to the public if you don't want to. Many famous artists and illustrators in the past used photos, airbrush, etc to help create their pieces.