Without knowing anything about your skills apart from the years put in, I would suggest a Senior Consultant grade would be the likely fit - unless you're bloody fantastic, but in my experience good contractors rarely translate into great consultants (no offense, it just seems like a slightly different way of approaching this which leads to some crossed wires).
Like other big consultancies, they are more likely to hire you at the top end of the grade below with the aim of promoting you within 6-12 months once you've proved yourself. Unless they are desperate for your sector knowledge.
In terms of pay... who knows. That's for you to negotiate and the grade pay ranges will be quite broad. If all your experience is from the consulting/contracting side you will be at the lower end of that grade, but if you have a lot of industry experience from client side, you will be more in demand. I think £80k+ would be a stretch, but again, I haven't seen your CV.