IMO the standard cart should handle the PA fine. There is no worry about flats, the frame is plenty strong and the wheels' low buoyancy are so easy to handle when plugging and unplugging the cart.
BTW, if you had a set of low (below the knee) waders you could launch directly from the ramp, stay dry and save yourself a lot of jockeying. The waders could be removed and stuffed into a hatch or cargo well when on the boat. A friend who uses cycling shoes does the same thing -- changes shoes once aboard.