Any reason Nikon over Canon? Only reason I ask is Canon is doing an amazing cashback deal at the moment. £140 cashback if you get a 40D, and a fair bit cheaper then D300, around same price as the D80 IIRC. I've done my homework on this, and I am getting a 40D. IMO it is the ideal camera for RC use (very fast, low noise at high ISO) and is cheap, and with the cashback I found it hard to turn down.
I agree the Sony camera doesn't feel right, and it's slow as well, so not suited for any kind of action. As for Canon size, the 40D is bigger than the D80 so it's not awkward and small like the bottom of the range models. And of course a battery grip is relatively cheap considering it makes it bigger (easier for action photography), doubles the battery life and gives the extra shutter release button for portrait orientated shots.
I'm not saying the Nikon is bad, or trying to discourage you in any way. From my research there is nothing between Canon and Nikon, it's just picking a flavour you like so to speak. But I just thought I'd make you aware of the cashback, as for me that's what confirmed my decision, £140 is a lot of money back
http://uk.youtube.com/watch?v=dbppTQfuJ8M (this is also quite good, the pc software looks great)