Well, I would do this:
1) 114060 ND Sub. More true to original, stainless steel, the true tool watch. Under the radar.
2) BLRO GMT II. Now you have white gold, a super classic dial-bezel combo, a GMT complication and the date and the cyclops. Done.
3) Platona. Now you stepping up in the material even further. It is unique in how it looks (gorgeous ice blue and brown ceramic dial).
So in my reasoning, you are building up gradually, a diverse collection that offers the best of what Rolex offers. You got your SS, Gold and PLatinum cases. You got your Diver, Pilot and Racer themes. You got your full diversity of color - black, red-blue, ice-cool brown. You DON'T get the cyclops on 2/3s of your watches, a feature I personally dislike. Also you dont have PCLs on every bracelet.
So That trinity would tick all of my Rolex sports watch needs.
Seeing as you have the Smurf Sub, I would go for BLNR GMT, and have some stainless steel in your collection, if you are SET on going with the Smurf. I just think a white gold submariner as a tool watch is over the top, it's the full Msport performance package on a 318d BMW. Just an overkill. But if you love the blue, I can't talk you out of it and BLNR arguably won't be enough. Just think a Sub ND is a very nice addition to a diverse collection, purely from an aesthetics point of view.
cheers!