That's quite a lot of oil to burn over 1000 miles. There's two ways to go with it, 5w-40 synthetic as the best for protection, 10w-40 semi-synthetic as best for the wallet.
http://www.opieoils.co.uk/c-656-5w-40.aspxOut of those, the best ones are the Fuchs/Silkolene Pro S, Motul 300V, Redline and Gulf Competition. The Motul 8100 X-Cess, Millers XFS, Shell Helix, Fuchs Supersyn and Mobil Super 3000 are good, cheaper alternatives.
Here are the 10w-40s we have and I would either go for the Fuchs XTR, Shell Helix, Millers XSS or Motul 6100
http://www.opieoils.co.uk/c-657-10w-40.aspxCheers
Tim