So you want to use their well established name to lure fresh newbies in? Im afraid they are in this business themselfs already. This seems to be the latest fashion in town. DB(FXCM), Citi(Saxo), UBS(Oanda), ABN Amro(Oanda), RBS(CMC Markets) and so on.
Saxo and Citi didnt merge (heh), Citi offers a saxo whitelable tho, IIRC.
What exactly does an Forex IB do anyways, except collecting a commission-split/kickback? What benefits would your clients have over going directly to DBFX, where they can open an account with a few bucks themselfs?