A LOT of Jesse's OD sound is from the Ric he was playing too... He did some electronic kung fu on it that made it have almost no resistance, so the thing was running crazy high output.
I also love DFA1979 and i love Jesse's tone. I've ALWAYS been a fan of old solid state amps. I get a crazy grind with my Kustom200, Peavey Mark VI and GK 400rb... Picking two and going through a 6x10 and 2x15. It helps to have a super high output bass (i can crank my ATK nicely!)
On the cheap, i would recommend running the Digitech Bad Monkey OD pedal... that pedal alone is almost an instant Jesse Keeler tone...
Here's an interview with him:
http://www.bassplayer.com/article/de...e/jul-05/10648
There are music videos with him playing a Gibson Grabber as well... but i've never seen any live video of them.
Good Luck!