Make both, have the TM bring up results from active stalls... i really cant be that hard since the data is already being pushed out in a new window form. Surely the coders can grab that data and shove it in the trust merchant. Allowing players to consign , search or simply make a stall (remember TM had a consignment limit + commission) Stalls also allow you to buy items. So using all that data just make an NPC that would retrieve that data in a fashion that would be easy to use and make use of BOTH systems