Heavy beaters shouldn't be causing "lag." Beater weight can affect the feel of the pedal, but any latency likely has more to do with the pedal itself.
Pretty expensive though. Are they plastic? They look like it.Im just gonna say this once.
How about some AXIS Sonic Hammer Beaters? They sound perfect for you, because you can change the surface of the beater in 3seconds, there are hard rubber, cork and felt surfaces that you can use, i guess you would use the hard rubber, as it is most similar to the plastic side of a beater but with less plastic SLAP.
Click here to check em' out.
Btw they are adjustable stroke length beaters, which you may need now or down the track. Either way i think these would be the best option for you.