Just a warning about Canon FD lenses, even with an adapter you will not be able to reach infinity. The only way would be to modify the lens mount on the lens.
For the Canon world the 200 f2.8 L has to be the best bang for buck. Great wide open and almost blistering edge to edge at f3.5. Well worth the $950 entry fee. Consider the price jumps to $6K for the 300 2.8 L
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Terry