I cover the NFL, so my equipment tends to be on the long/heavy side. I currently use a 400 2.8 on a Manfrotto 681B monopod with the RRS clamp and head. After reading your reply as to what the use would be, I think you have to decide which to you is more important. If you what to do birds and such, then a good tripod and head should be looked into. If you want to do sports, a monopod will be the better choice. Most sporting events won't allow for the use of a tripod anyway for safety/insurance reasons both for you and the participants. Doing sports means you have to be mobile and a lot of times that means moving very fast. As in getting out of the way. Also the ability to move to various locations quickly as the action progresses. If you want to do both, get both a tripod and a monopod. The monopod I use is a solid performer, collapses small and is rated for about 60 lbs. but at only $60. Carbon Fiber would be nice(because of weight) but I can't justify the cost for my use. As I said, you have to decide on your uses, weight, desired mobility, and cost. You're spend a lot for a very good lens, so make sure of your decision on how you are going to support it.