Just installed Nitto RB-009's and Cane Creek 200TT's. Love the look and how well it works for me. Never even considered putting levers on the flats. This is my training bike and around town cruiser with the wife. Would rather have the TT levers than cross levers.
As for whether the RB-018's will work with the 200TT's, according to everything I have read they won't. Nothing supposedly can. That's the ONLY reason I got the RB-009's. I wanted the straight bullhorn bars and these were the closest I could find that I liked that worked with the 200TT's.