Hate to state the bl**ding obvious but as the stuff is coated in roll form there shouldn't really be any problem getting hold of it in suitable widths/lengths. However agents in some territories seem to have a phobia of stocking them, possibly in case they get landed with leftovers from any minimum order they have to place. Ilford/Harman have quite a few stock lines that any distributor worldwide should be able to call on anyway.
Their specials also shouldn't be too daunting - they have done a number of special rolls for Silverprint, (which we now stock ongoing) on the basis of an order for 10 rolls of 42" (106cm) x 10 metres, or the equivalent area in 20". It's worth trying to set up an order with your supplier if you can go to that sort of size (or split it & sell the balance).