Wouldn't that put you over your $600 budget? I've owned both the CB-5 and CF-30 and think both would fill your room up fine. However, if I were you, I would rather have the S10.3 sub vs the sub that comes with the Takes. From what I understand, the S10.3 is a very capable sub and is a great buy at its current price. I'd also rather have the CC-5 center as opposed to the Take center, but that's just me.
If you're getting all new, 5.1 speakers at the same time for $600, I think you need to compromise. I would rather have a better sub and center with bookshelf speakers than have the CF-30 towers with a lesser center and sub.
Where are you located?