@Rifqi
My suggestion, out of complete macro ignorance, is to obtain the body you decide upon, then see how the lenses you have perform with this body. A DX lens may actually perform well for certain situations, i.e., near square format on FX, and the only way to see what coverage you have is to try it. My only example is the 10.5mm, which I have found I prefer to the full frame 16mm on FX, as I grew up in the era of the round fisheye and the 10.5 is similar to this. Your photos are so nice, I might suggest waiting to see what the new DX (D400 if it actually gets here) has to offer, as the presumption is that a pro DX should offer more, for me at least, than an entry level FX, (D600).