money is not the issue I just want one thats compatible with the T2i
Yup, this. I had one for my t2i and my 7D (different plugs). You can also use your laptop and the supplied software but I don't really like doing that personally.
I know it's a little late to jump in on this thread but I would like to know which cables you used to get the calculator to work with the 7D and where you got them.
Any help would be much appreciated.