I don't like the idea of bolting the lens straight onto the monopod so I am also looking at the RRS MH-01-40LR: Monopod Head ,
I'm not sure what you are shooting but unless you really need a tilting head you may find that you don't use the feature all that much. I mainly shoot sports which doesn't require a lot of up and down positioning so I mount my camera/lens to my monopod with a RRS quick release clamp and either a lens or camera plate. I had a cheap monopod head for a while and never once tilted it so I decided to get rid of it. I know it is personal preference though but just trying to save you a little bit of money unless you really think you will need the feature. I can see where BIF or aviation shooting might call for it.
Currently I use the Manfrotto 679B monopod and it is just fine for what I need and has always been very stable. However, purely out of want I'm getting a CF monopod. I looked at the Gitzo GM2541 (expensive) and the RRS MC-34 (really expensive) and ended up deciding on the Jobu Design MCF-284 (reasonable). From the reviews I have seen it is a good quality piece at a decent price.