Altadis Fox and Hound in bulk; Sutliff's Westminster; G.L. Pease Westminster; Forg Morton Original.
Pipes and Cigars has good tobacco pages that identify both the type of tobacco, in this case English,
the constituent tobaccos in the blend, and the strength from mild to medium to strong. There is
a wide, wide selection of mild-to-medium English blends.
Two other favorites are Nat Sherman 536, from the NYC tobacconist (you could order by phone, but
they don't sell online) and Dunhill My Mixture 965, which may be a little strong as a starter English blend.