Put the plastic down and take a deep breath. Ok, with that out of the way, how much would you use either of the lenses that you plan on purchasing? Do you use the 200 often. I think John had a great point in selling the 200 to fund the 135L. You can do that later. I would get the 17-55 if you must trade off something and then sell your Tammy. I still have my Tammy and think it is a great lens that I use for indoor purposes only. I have the 24-70 now and it preforms close to the same, minus the little buzz from the AF. I think the whole decision would be how much would you use the lens that you plan on purchasing and go from there. Look back at your photos and see the focal length you used the most out of the pictures you have and there should be your answer. Good luck!