The closest thing to the Defender's are the Cooper CS4 Touring in the T-speed rating. They are rated at a UTQG of 780, Traction A, and Temperature A. I had them on a 2003 Chevrolet Impala LS 3800 that lasted 138,000kms of 60/40 highway/city and Canadian winter driving and they were very quiet, reliable, predictable and priced very competitively.
Discount Tire Direct has them for $114USD per tire in the 215/60/16 size int eh T-speed rating. Best tire for long life, and best of all they are asymmetrical - good for tire rotations.
EDIT: Plus you get an 80,000 mile warranty with the CS4's. FWIW.