For the first movie, my inclination would be to use the Trickster as the main villain, with a selection of Rogues as the B-act/patsies. Basically, gadget using science villains are a problem for the city; Barry gains superspeed in accident, beats a bunch of the Rogues; mysterious 'Trickster' shows up, convinces them to work as a team; Flash beats them again, in a much harder fight showing his improving skill, and they are all arrested.
Then the Trickster shows his true plan: he'd infiltrated the police department well before, and getting all the Rogues arrested led to all their technology being delivered to the evidence vault. . . and his hands. Flash now has to fight an opponent who has the combined technology of the Rogues, and a far better plan for using it in a way that would make Barry's day hell, forcing him to use every ounce of cleverness and speed to win.