Which Oxygen Sensor To Buy?

I've got a 2005 Honda Accord V6 CM 3.0 model.

Anyways i have this two codes showing up and was just requiring a little more info if anyone can help.

OBD Codes - P0137 and P0138

http://www.obd-codes.com/p0137
http://www.obd-codes.com/p0138

My question is this the same sensor just showing two different faults?

How many sensors do Accords have? If anyone can link me to an eBay link for a reasonable priced sensor replacement i'd really appreciate it as i'm unsure which one to buy.


Cheers