u could get an epiphone dot great guitar for an awsome price

I personally would recommend a fender telecaster.

Otherwise, a more acoustic oriented type like epiphone 335 or 355.

And if you have the money, you should look into a gretch

I would go with that EPI B.B. King guitar you mentioned.

Here is another, less-expensive guitar that would sound great on the blues ——
http://guitars.musiciansfriend.com/product/Squier-Affinity-Series-Telecaster-Special?sku=515115

es335 or something equivolent.

depends on what sort of blues you want it for.
Telecaster is always a good choice.

les paul es

I like Gibson 335s or similar, Telecaster is great for certain sounds, but really, I’d recommend you take you sweet time and sit in the guitar rooms and spend time holding, playing and really getting the feel for the tone and what style fits to your body comfort. Blues is blues, can be played on a cigar box, a stick and catgut, so lol, just take your time choosing. That’s part of the fun of the hunt! See what folks are playing in the clubs, etc.
But one hollow body electric is really nice to have. Wish I’d never sold my old Ibenez. I forgot the model # but it was that big blond George Benson style. I have shoulder pain issues and it was awfully heavy.
I’d go for what you like, research reviews of any potential purchases and root out the best deals. Try to swing for a few freebies (a stand, a strap, a set of strings). Never hurts to negotiate! Good luck!