Thanks guys.
I don't think that a 100-300mm would be too long as maybe the longer the better

I never had a long lens when I had SLR's but in my digital days I've had a couple of lenses that went to 300mm and that on APS-C meant 480mm so matching that would be nice

and that's something I've not done since I sold my 20D. A long lens would come at the cost of more money and more bulk though. Basically I just like a longer lens available now and again for taking pictures of far away stuff and a really nice shot of the moon is something that I've never had the length to get. Other than that the different shooting distance and perspective using a longer lens is nice now and again too. Maybe 150mm will be good enough and maybe I'll give a 45-150mm a try