Sarah Conner Chronicles
Actually - as someone who has (legally) watched the pilot of Sarah Conner Chronicles, I think it could work.
It's pretty grim (including the bit that's now infamously been dropped from the pilot when the substitute teacher in school turns out to be a terminator) and gritty. Some tongue in cheek too though (thank the gods). Very cool time travel stuff from both sides - anyone can be prepared if they send agents back in time with enough years to build more time machines and resources.
Apparently they spent about $8m on the pilot - only a small jump more to having a film especially with the pace the pilot sets.
However the one sticking point is if they can keep up the plot quality. This could be the problem with the films too of course.