They don't want a 6 or 7 though, they want a keeper who opens
I don't see the need if you have two opening batsmen. We have plenty of batsmen in this country who open the batting in the county scene who are more prolific than Kieswetter. Sure we have Kieswetter, Mustard, and Davies to name three wicket keeping opening batsmen, but they aren't the biggest run getters in one day county cricket. For me, we could quite easily find ourselves a prolific opening partner for Cook, and bring in a Foster, Reid, or Prior.
Look at India, they have two opening batsmen and Dhoni at 6 or 7. Australia have Watson and Marsh opening, with Haddin down at 7. Sri Lanka's keeper bats in their middle order. And South Africa have Smith and Amala opening, who arguably are the best opening partnership in ODI cricket right now, and their keeper bats in the low middle order. So if it works for them, then it can work for us.
2 years ago I might have agreed, but since then Prior's keeping has been pretty special - certainly as good as any other current Test match keeper
He still snatches too much for my liking. When you watch Reid and Foster their glove work is by far superior and neater to watch. But Prior has improved a lot since he first gained his place in the team, and right now he is one of the best keepers in the test match arena. However, I am still of the opinion that there are better glove men in cricket than Prior.