As Stratamania said, the Floyd bridge kit comes with the retainer bar. Be sure to install it, as, just as Stratamania said, when you tighten down the string clamps, if you don’t have it…all six of your strings are guaranteed to go sharp, and then you’re playing a guessing game as to where they should be, and finishing up with taking some of the travel out of your fine tuners. Ain’t nobody got time for that. I installed locking tuners…on my Floyd Rose equipped Soloist, just to cut down on the string change time.
Anyway, yes the bridge kit comes with the retainer bar and screws for it. If memory serves (DON’T just go and drill this hole, please measure), a 5/64 bit was PERFECT for those particular screws, at least the ones mine came with, and I just bought it a couple months back (installed it last week).