I want to thank everyone for their time and input - I find your comments very helpful.
In review, I do not think that I need to large telephoto at this point but will probably add one to the inventory as time passes.
I would like to wrap this up as best as possible.
I think there are several choices:
1. get the 20D with the 18-55 lense and add a telephoto like the Sigma, or
2. get the 20D body, and then purchase two lenses, one shorter range and one longer range.
What do you guys think of the two options or is there a third?