I almost feel foolish suggesting something as old fashioned as 023's, but I still think they are brilliant. In an ideal world, the PR2/PR3 is probably superior, but when things start to go south, the 023 is just so forgiving. You have to be a real clutz to make them let go because they just complain instead of giving up. On a proper long journey, such as the one you are planning, I would be thinking of fitting new 023's at least two weeks before hand so they were properly broken in and I was properly used to them before setting off. They will survive low pressures, bad weather, being patched and still get you there, and when conditions are ideal, they are still more then good enough to put a bloody big grin on your face. Could you get an extra 3 or 4 mph on that 100mph sweeper if you were on PR3's? Perhaps. But will your PR3's get you to your hotel after you have plugged the hole left by a nail 1,000 miles earlier?