Alright brother, I was going to wait until the 'Cuse vs Huskies game was over, but that ain't happening.
You've heard from a B-1 cat and two Talon cats, obviously we (the Talon bubbas) are partial to the 130.
You have been given advice on the location and mission of both aircracft, so its up to you. Since you still seem up in the air I will leave you with this.
You know how you performed in nav school. If you liked navigating an airplane, if you flew low level (I assume you do low-level in Nav school, I'm a pilot) and you liked it and you were good at it, then pick the C-130. If any of the above didn't apply, pick the E-8. The bottom line is you can't do any damage at 30,000 feet or whatever altitude the JSTARS flies at.
P.S. - I realize both missions are important, and require skilled crewmembers at every crew position. I am not trying to start some stupid internet flame war. The bottom line is low level is dangerous if you suck.
Fontus