There are literally 100's of 'classics' you could learn but the list of artists you've got so far is a pretty good list from someone who knows 0 about blues! The good thing about blues per se is that 90% of artists do 'covers' of previous pieces so I'd get something realy simple and play around and expand on it - it's good to steal!
I'm probably being way too predictable but I'd add these to an essential blues list
Hendrix - Red House
Boom Boom - John Lee Hooker
Dust My Broom - Elmore James
All Your Love - Otis Rush
Five Long years - Eddie Boyd I think was the original artist but listen to Clapton's version on From The Cradle - he still has 'it' on that track!
SRV - Texas Flood
SRV - Couldn't Stand the Weather
If you want to immerse yourself into the blues genre listen to as much Freddie, Albert and BB King you can get hold of and mix in Buddy Guy (get the albumn Can't Quit The Blues its outstanding), Jimmy Vaughan, John Mayall and if you can get hold of it (or download it

) get hold of '
Blues Jam in Chicago' by Fleetwood Mac - that's the Peter Green era, not the Stevie Nicks / Lindsey Buckingham era! Otis Rush plays pretty accessible stuff too.
The more modern guys is a bit harder as there are sooo many good 'blues' guitarists around now. But as you know your rock stuff I'd go and look at Walter Trout, Joe Bonamassa, Robin Trower, Rory Gallagher and
Robben Ford (jazzed tinged too!). Technically you'd probably be able to lick all the guys but they put all the old licks in a heavier and more modern context.
No one could ever cover all angles as it's a huge topic but it's nice to see a player wanting to expand into another musical spectrum - feel free to pm me as I could pap on about blues all day
Good luck!!!