Hi doug! I think that the light you linked would work fine! My old set up used an old school sun system 4" air cooled hood, and I mounted a DIY ballast kit on top of it (the kit cost $35 lol). It worked GREAT for me until the ballast died, but what you linked looks like a higher quality product than what I used.
So long as it uses a magnetic ballast, you are OK. The 250W and 400W CMH use magnetic ballast, and the bulbs below 250W use Pulse start metal halide ballast.
Make sure you get the Phillips HSP retro white CMH bulb though, that is the only really good one on the market, and it is the only one rated for an open fixture.
depending on your flowering chambers size, you may not even need the LED's with the 250W bulb, but I am sure the added LED's wouldn't hurt!
Let me know what you go with, and how it works out for ya!