The Gills had been keen on signing Benson but were unable to agree a fee with the League Two club and have moved on to other targets.
Stimson said: "I think Dagenham have stated the money they want and it's something we're not going to get involved in.
"We've moved on. We definitely need one striker and there maybe another twist in there if we can do it.
"We've been working on a few things throughout the summer and one or two things are coming to the fore now so they might happen."