Well, whatever blows your hair back, man.
You'll get fine results either way.
It's just more exxy to run 4x600, especially in acquisition, as you note. It's also another ~600W out of the mains to run the 4x600 arrangement, which adds up to +7.2kWh/day. I pay 16c/kWh, so it would be another $1.16/day (34.56/mo) in power cost. Adds up.
However, if all is going well for you, $35/mo is a pretty insignificant cost. Consider also that either the 2x1000 or 4x600 arrangement will yield almost exactly the same.
While you may be enamoured of more point sources of light, it probably won't break your arms to turn plants around now and again. If you're using batwing reflectors (like the large
Adjust-A-Wings refs), which spread light quite well, you may not even have to turn plants.