Alex, we've got similar kit.
We both use a Canon 100-400 L IS lens and I've got a Canon 10D, Nick's got a D60. I bought my equipment after asking Nick and Damien Burke what I needed - and I have to thank them both for their help since then
I'd love a faster lens for the evening displays at Old Warden, but the prices of anything more exotic than my current lens are prohibitive.
Rob