I have this one:
http://www.etrailer.com/mm5/merchant...uct_Code=49586
I also have a 2720SL with swing-away hitch. Works great. You don't need an installer for the part that attaches to the TM. You *might* need some help with assembling the part that goes on the TV, or if you have some big wrenches you can do it yourself (I did). I still need to weigh everything to make sure it's all adjusted optimally, but at no point in time have I been worried that the swing hitch might not be able to take the weight of the WDH.
At some point I'll have pictures, if you want.