I would be surprised if you find anything in that width. I have seen cheap lustre in 8.3 (A4) width, but not uncoated bond.
If you can find someone with a chop saw, then you could cut the 24" roll down to two 8.5" rolls, but I would also be surprised if the printer will feed from a 8.5" roll. The manual states a 10" minimum width for rolls, even though the driver dialog allows setting a width of 3.5". I have tried feeding sheets, and again you can set it for 3.5", but it will not feed anything less than A4 (8.3 inches).
So, cutting the 24" roll into two 11" rolls. may be your best option: print portrait and cut at 8.5 inches.
Brian A