Thats going to be tough, most dont want the travelers to take overtime. The ones that do only want the travelers to take it if the shift is going to be extremly short staffed without you . There are some that are so short ie one assignment my company had 9 RN's in this ER would let you work as much as you wanted- as long as you remained safe to do so. As far as when your looking for an assignment the recruiter might not have this information but you can alway ask when you talk to the hospital.
plenty of overtime where I am. dont know what the set up is with other agencys, who send nurses here, but the hospital is glad of us working it, as the regular staff dont want it. I have been working an average of 150 hours in a 2 week period.