I prefer the Lee Oskars for tone. Their only shortcoming is that the cases don't tend to be very rugged.

The thing you'll have to learn for blues is bending the notes.

It's actually very hard to explain how to do this, but it's done by kind of narrowing the mouth and squeezing to get a bent note - you really need to be able to bend the note down to the next one underneath it to play blues effectively.