this is another one from ebay, just in case you want options.
http://www.ebay.com/itm/Curt-Class-2...9c3510&vxp=mtr
but it looks like the HitchFinder.com one is cheaper.
Now, not to confuse you anymore - the one from Hitchfinder is a Class One, meaning it can tow up to 2000lb (realistically, that's more than enough for a bike + trailer). The one from ebay is a Class Two, which is up to 3500lb. I don't know if a passenger car should tow anything that high. but the choice is yours. I will just stick with Class One and be done with.
Lastly, you will then need to install one electrical component:
http://www.hitchfinder.com/products/...onverter,51-57
you can do this yourself too.
and yes, you can certainly install the hitch yourself. one word of advice: don't tighten all bolts UNTIL both left and right sides are in place. If the hitch is just slightly bend (due to shipping or manufacturing defect), you will have a nightmare aligning the hole together.