No you cant just get the axle back part, you have to buy the whole system. I tried to do the same thing but its only sold as a complete system.

I bought mine from a seller on Ebay that only sells the Brospeed systems. He let me have it for $420.00 + $20 S+H
The Accord store wants $449.00+shipping for it.
Here is the guys site. http://www.proexhaustproducts.com/