Fabulous Thunderbirds, 3 Kings, Ronnie Earl & The Broadcasters, Albert Collins, Duke Robillard.
I would learn as much of their material as possible and you will have a stock of tasty blues bass lines.
Learn Stormy Monday, Need your love so bad etc.
Slow blues bass lines, swings and shuffles are in abundance on any albums by the above.
Johnny B Gayden (Albert Collins )Tommy Shannon (Stevie Ray Vaughan), are the two blues bass players that rule the roost IMHO.