Item Requests or Store Orders for store supplies (SIM 13.2.4)

I'm looking for recommendations on how to best handle stores' needs to order replacement non-merch consumables (e.g. receipt paper rolls, bags, etc) via SIM. In our environment, replenishment of sellable goods (i.e. regular merchandise) is handled almost exclusively via a push model - any requests for merchandise are handled by our Allocation team (outside of SIM). With that said, we want to limit a store's ability to order regular merchandise but still be able to allow them to order supplies.
Can this be accomplished in SIM when it is integrated with RMS? We've taken a look at using Store Orders but it seems any SKU can be selected for order, With Item Requests, we have the problem of ensuring the user orders from WH and not from supplier directly.