It would be feasable. The ATP course does not prep you for the written exam. Unless its changed in the last few year, you were expected to show up on day 1 (of 14, which includes all checkrides) with all written exams done. Most folks crammed using either a dvd course or the gliem test prep book.
The ground school we did at ATP (7 days long) mostly went over the aircraft systems in detail. aerodynamics and Vmc were the major topics. For many, it was the first time they ever had to teach or speak in public. If you feel your ok with all of the above (or can teach it to yourself) then you may find a course like ATP's a waste.
If you can find a good CFI who's had his CFI for at least 2 years (required to sign off initial CFI applicants), then your golden.
If you'd be willing to go to Alabama you may want to call Joey Sanders in Jasper and see if he know anyone with a Seminole who can do your CFI training (outside of atp, which is hard to find in some places). Last I spoke with him he had a British Gnatt in his shop he was rebuilding for air races.
