Will you lose your REG testing fee if you postpone REG?
If not, I would postpone REG and take FAR again in Mid-October. Then take REG on Nov. 30th (if slots are not already filled up). You could also push back FAR to late-October and test for REG the first week of January. Tax season doesn't pickup until late January (at least for me).
If you will lose your REG fee, continue studying for REG and test for FAR in January.
With a 64 it looks to me like with a little refinement you could pass FAR. If you're using Becker, I would spend around a chapter a day reviewing (6 hours per chapter), including 20-30 questions for each chapter covering all topics. After that, quiz yourself 10 questions a day from each chapter (90 questions a day in total). Your goal should be to get at least 80-85% correct everyday. Supplement your quizzing by using an outline. I really found the outlines Becker provides to be very helpful. If you use the Becker outline elaborate on it. (It took me about 30 to 40 minutes to get through one page of those outlines).
As for the TBS, you should only study two things – Journal entries and the research task. (Tip for the research task – use quotation marks around phrases, i.e. “cash flow” not cash flow. On my exam using quotation marks allowed me to finish the task in under four minutes, this includes spending two minutes double checking that I typed the reference correct into the solution box.)
Pump yourself up! Plan to spend 25 hours a week studying. If you work in tax (which you seem to indicate) 25 hours should be reasonable during the slow fall months (post 10-15 at least). If you find you are not studying 25 hours a week, just tell yourself, “You deserve to fail.” Then prove yourself wrong the following week.