Well, most assignments are for at least 36 hours per week, and won't be willing to work around your schedule at another job, so it would be tricky.....
Also, I see in another post that you are still in school. You will need at LEAST 1-2 years of experience as an RN before traveling. Your experience as a surgical tech, while very valuable, will not count as "nursing experience" when it comes to travel companies and facilities. So after you graduate, you will need to work as an RN in your chosen specialty for 1-2 years before traveling.....