@bob williams
I suggest the 300 f/4. It has decent macro capabilities and twice as fast as your 100-400 from 300mm on. I have one (it's my only lens) and love it. It may not be a huge step up, heck you'd make money selling your 100-400 and buying the 300. The 70-200 2.8 is not a good wildlife lens, the f4 IS version is considered to be much better for birds, etc. If you need something telephoto and something fast, you're stuck with the $4000 300 f/2.8. But I think the IQ of the 4/300 is better, but not quite "outstanding".
@bill W
Why do you want a 70-200 for your hummingbird gardens? As you know they're tiny and so max magnification is very important. at least .2x is nice. Have you considered/do you have a 100 macro? Wickerprints has shot some beauties with that lens. just an idea. Good luck with that 7D!
brendan