Roger, harmonicas are made in every key in the chromatic scale. It seems easier to for you to pick the tuning that suits your voice and have the harp player choose a harmonica to suit yours.

Terry plays "cross harp" which means he plays a fifth above the nominal key of the harmonica. If you tune your guitar normally and play in the key of E, your harp player would use a harmonica in the key of A.

Since Terry spent so much time playing along with Brownie McGhee, who used a standard-stringed guitar, I would be inclined to think he didn't particullarly favor an E harp.

Most amateur harp players I know start out with a C and then later add a D to their collection. This means they can play blues with a guitar tuned to G and A respectively. Next in order of frequency are the F and A harps which play with guitars in C and E respectively.

Ah well, sorry to get so bogged down in harminica lore. It happens to be an interest with me at the moment :)

Murray