Why you wants to trigger two concurrent request in the same time? It not seems like a good design.. Please describe a case little bit more so we could suggest something else.
I use quite a lot of suggestion boxes and most of them use basically the same query with additional filters here and there.
I thought Seam's EntityQuery with the appropriate restriction strings whould be perfect for the job but I don't know how to set the values of the EL expressions in the restrictions for a particular suggestion box.