As mentioned before, unless your shooting motorsports, concentrating on fps for what you want to use the camera for forget, kit surfing at 60mph, try 200mph motorbikes or 600mph aircraft and even then you don't need the machine gun effect of fps.
Mainly you'll be using it indoors, so either a fast lens or good iso performance is required. It pains me to say this but canon are behind the curve ball with this, Nikon has moved streets ahead.
Your problem is a decent setup for £800, which especially nowadays isn't as achieveable as it once was. Nikon D90 Body on its own is most of your budget all gone without getting a decent fast lens and even 2nd handmarket prices have rocketed.
But in answer to your question, for the ISO performance alone, I would go for the Nikon D90. I've been severely temped too switch (get rid of 1D Mkiin, 20D and L lenses) and get the D300 and Nikon 200-400mm f4 lens and 300mm f2.8 but it always comes to $$$$
Peter