Thanks everyone for your replies, suggestions & links. At the moment I'm probably looking at getting three zooms - a standard, a wide & a tele zoom. Primes will have to wait unfortunately, until I recover from the initial financial shock of this purchase!
I've pretty much decided on the Sony 24-70 F2.8 GM II for my standard zoom. For a wider zoom I'm thinking the Sigma 16-28 F2.8 is looking pretty good. I doubt I'll ever need anything wider than 16mm. As far as tele goes I've got no idea. I'd like to get out to 400mm at least but unsure whether it's better to go for a superzoom (for want of a better term) or a shorter zoom & tele converter. The shorter zoom & tele converter has the advantage of being a bit more compact too I guess.