Those are FM modules so you really don't need to worry about a preamble. Just use the carrier detect pin on the receiver to determine when it's receiving a signal. Radiometrix probably has some detailed instructions for their use.

Also, you can ignore the advice re breadboards. The modules are basically self contained and all you need the breadboard for is the interconnections, power, etc. the breadboards won't affect the RF modules.

And the antennas you're using are fine.