How wide do you have to go? What kind of volumes? Photos?
In the Canon world, I believe QImage can print up to 44" with a Pixma Pro 9000-2. The factory print-driver is limited to about 23" or 26" length (but I am not a QImage user, so "consider the source")
Otherwise, I admit ignorance about Epson printers, which probably have the most options regarding roll paper.
My speculation is that the capability of using roll paper is more likely with larger printers than A3. (about 13" in the USA).
I'd also be concerned about whether the roll mechanism ... and cutter ... were robustly built for your needs and expectation, whatever they are.
HTH