What you need to ask yourself is "how soon are you thinking to add corals? how certain are you you'll add some? and if you think you will, what types/species?"
Reason is that you're setting yourself up to either make one light fixture purchase, or two. And one is plenty expensive.
400watts over a 150 isn't really a ton of light. Less than 3wpg, which limits you to lower light corals, and I doubt you could keep any sort of anemone (not a coral, but everyone gets the anemone itch at some point). 4x165 gives you over 4wpg...which opens up more corals, and you could at least keep a bubble tip anemone.
If you only ever wanna keep mushrooms, the 4x96 is cool. If you want to try hard corals and anemones, just get the 4x165, or look into metal halide with PC
If you have no corals, then the bulbs are mostly for looks. With corals, you need to keep bulbs fresh enough so the corals thrive. 9-12 months with normal usage (10-12 hours a day) is the spectrum duration.
Keep the old bulbs though...the daylights can still be used for freshwater aquariums, including planted tanks, until they no longer work. Plants aren't as picky about spectrum as corals.