will this ballast be ok

175 MH over a 29 should be plenty for those. Just make sure you get a good reflector, I've heard a lot of good things about the high-efficiency reflectors, like LumenArc and Lumen Brite. Expensive but well worth it. All you'll need is some sort of gear box for the ballast, a switch, a power cord, and the reflector and socket.
 
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