split hive, split brood?

[tlynn]

I have a new brood box built and am going to put it on our first colony with the intention of getting the queen to add brood to it until end of August, at which point I will pull the box, put it on a SBB, buy a new queen (or should I let them make one?) and have our 2nd hive.  Question is when I put the second box on my current hive, should I mix in some of the egg and larvae and honey frames into the new frames or just put it on?  Frames are new plastic foundation that I have rolled onto an extra coat of wax.

Thanks!

Tracy