1000w vs. 600w for a small set-up/scrog

Ok, I have a bubbleponics system with a 400w switchable lumatek. I've been wanting to upgrade to 1000w 120v, but I'm wondering if this would be totally overkill. Basically I want to minimize time taken to yield. Ofcourse, the obvious alternative to my small space is a 600w 120v.

Basically, I'm asking, "Is it foolish to buy a 1000w ballast for only 2-3 plants? Should I just stick to a 600w?" I've been ScrOGing here lately, and I know that scrogs use less lighting more efficiently. Regardless, I could use some help from the pro's out there.

yes it is foolish to buy the biggest possible for only 3 plants lol
also buying a larger light isnt going to reducing how long a plant takes to grow, they can only grow as fast as they can grow

^^So true^^
If you're going to continue to scrog, maybe add another 400W. You don't need deep penetration into the canopy. This will give you much more light intensity (watts per foot) and should increase bud size and yield. Both good things, but nothing will speed up the flower cycle more than a day or two.
Fred