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It is best to go with the direct adapter that takes you from the EOS camera to a T mount. So if you have telescopes with T threads, here is the link to a simple and low cost adapter:
http://www.optcorp.com/product.aspx?pid=802&kw=canon eos t&st=2
There are times where you do not want to add any un necessary length to the system with multiple adapters, because you may not be able to focus in all cases with the extra length. Thus the recomendation for a single adapter.
As a future note, for a full frame camera, you can get some loss of image in the corners because of the size of the hole through the middle of a normal style T adapter. There are some special solutions that can attach an EOS full frame camera to many telescopes, and maintain a full opening that fills the whole sensor.