I want to get more research experience and for right now I'm hoping I get a position at the NIH as an IRTA. But if all that fails, would it be practical to do a year long post bac mainly to get better research experience?
No, this distinction is not purely academic at NIH. If you are an IRTA, then you are a trainee and therefore are paid out of a different pile of money. If you are a lab tech, you are hired by the federal government (or more often you contract with the gov't through a 3rd party company) and therefore get paid more, get benefits, and are allocated money from a different pot. They are not interchangeable.