hello i got 2 175watt magnetic ballast with the capacitors and the bulb holder for sale there use but both are in good working order i just upgraded to 250 icecaps i think i still have 2 175 watt 10k bulbs also but there old u can have them also if u want $50 takes everything im in queens
"A" (single) metal halide will not be good for a 72 bow, you will have a lot of shadows because of the center plastic brace and typical coverage is 24"x24".
Two lower wattage (150W or 175W) with good reflectors will do much better.