hey mate
sx40's are defintely a good bream lure, i find berkley bass are also a good bream and flattie producer. if ur not getting any hits on eithor slow it down or speed it up. just try and change it around. also use lighter lines, jigheads, rods and reals. it really is necessary if u want to catch good numbers of fish. try around canals if u have any near u, casting to jetties and under boats, mangroves are a good target. try everything and u should start getting some good fish.
have fun fishing