I got a quote with CZ's, and love the price...but I am super nervous because it is non-refundable. I am pretty sure I'd be OK with the color but my diamond has a tad of warmth and if the cz/s are suuuuuuuuuper sparkly it will look odd.
Have you checked into Wink or Chris CZs? Those you can get with warm colors so that they compliment your center stone instead of competing with it. There may be others that do this, too -- I'm no pro at this.
Or have you thought about a halo in colored gemstones instead, for unique personality and to really make your center stone pop? I was shocked at how cheap lab-created rubies and diamonds are (cents, not dollars!), and they have just as much hardness and durability as the real thing so they won't wear over time like CZs do.
Maybe colored gemstones on the inside halo and warm white CZs on the outside halo?