From what i've heard, you have to be hired by the FAA by the time your 28 years old. Now that doesn't give you much time to go through training which will probably take a couple years since you're already 27. But the good news is, that I believe the age 28 rule is only if you work as an FAA controller, you can still be a controller at a contract tower and make really good money, as in 60k to 70k to start. The reason contract towers must pay more is because they want experience before they'll hire you, which means someone would have to quit an FAA job and go work for them, which suprise suprise, doesn't happen too often. But if you can get on working a towered field for a couple years, I would say you have a really good chance of getting hired at a contract tower.