i have a 150 tank, and i have 3 175 MH in it with 4 vho actinics. we started with 2 mh and we got this dark V in the middle of the tank from the stretcher on the tank. put a middle one in and it looks better. we did the mh DIY and bought m50 ballast at light store,($60 each) and ordered the bulbs on line.
so, i would think you would like the 3 bulbs, i like the accent of blue actinics, and for before and after the halides come on/off. you may see the the "V" in my pictures online. I have some older photos in there somewhere.