if i were you, i would use 2 single pedals. and i would put the 2 kick pads in the same iron bar, one on the far left and on on the far right, trying to have them turned to each other. having 2 kick pads and using a double pedal in one and the 2box pedal (which is way inferior) to the other, and having 2 kicks with same sound, is pretty bad. imo always .
if dw 5000 cant be made into 2 single pedals, you are in a very bad situation. if i were you, id sell the other kick. having so many cymbals and 2 floor toms is awesome. you could also have 2 snares instead. one picolo and one normal. it is awesome
just my thoughts