Unless you have ESC's that can switch between BEC and OPTO, the short answer is no. Based on this, I don't think you do:
http://www.hobbywing.com/uploadfiles/sx/file/manual/HW-01-PL.pdf
The following is a very good read (scroll down to BEC vs OPTO)
http://aircraft-world.com/prod_datasheets/ac-esc.htm
The BEC just cuts down the voltage to your board/receiver so you can run everything off of your main battery without supplying too many volts. OPTO makes the connections optically to eliminate noise and give a cleaner signal between the ESC and the board/receiver, so to get power to the receiver with OPTO, you would need to either run power from your main battery to your own BEC, then to your receiver/board, or you need to run a separate battery altogether. Some say if you don't run a separate battery with OPTO, you won't get the noise eliminating benefits.
You'd need to read your board manual to get information on how to connect your ESC's with built in BEC to the board, but in a lot of cases, you'd remove all of the red wires to from the ESCs to the board,
except for one to supply sufficient power. Also, your board will pass power to your receiver. Some boards have built in BEC's, so removing wires may not be necessary, but it varies. Also, if you have OPTO ESC's, you will normally leave the red wires all intact because in the case of OPTOs, the red wire typically draws power from the board/receiver.
In the end, it doesn't look like you'll be running OPTO with those ESCs, but it gets more interesting because the A2 has a separate power supply unit - so if you're using that, you will likely need to remove all of the red wires from the ESCs to the board so you don't damage the board. Check the manual/instructions to be safe though. I'm guessing it would give explicit instructions on how to connect them. Just make sure you remove the pins and wires cleanly in case you need to add them back for whatever reason.