Sorry to answer so late but I have been away from my pc for the holidays (about the only time I get a break...).
I ended up taking the board certification with the American Academy of Nurse Practitioners. Which is why I go by NP-C instead of FNP. My degree is in Family Practice, but the AANP sanctions NP-C for Nurse Practitioner Certified. I applied to ANCC, but got such a run around and delay for taking the exam that I contacted AANP. AANC wanted a boatload more information and paperwork filled out. I would have had to wait almost six months to take the AANC exam, while the AANP wait was only three months for the computer version, or two months for the paper and pencil exam. To my knowledge the AANP is the only certifying agency still giving the paper and pencil certifying exam.
Oh yeah, AANP cost for taking the exam was less than AANC. I got my results back in four weeks, but that was because I took the paper and pencil exam. Other NP's I know were notified at the end of the exam(the computer version) with AANP that they had passed. The AANC takes approximately six weeks to notify you if you are successful, and they do that by mail. Don't let my situation influence you, contact each agency and get their song and dance before you decide.
Texas issues a 90 day intermediate permit to practice, but wants you to take the exam during that time. I did not apply for it because of the delay of both AANC and AANP in setting my dates for writing the boards. Whatever you do fill out all the paperwork correctly the first time, photocopy everything you send, and send everything via registered mail with return receipt requested. Hope this helps.....good luck.