Being a new FNP grad I would encourage you to find the program that meets your goals. Being an ER nurse for many years, I also debated between FNP and ACNP. I am so glad that I completed the FNP program. The main question I found is "Do you want to work in the hospital or outside the hospital?" I knew for sure that I wanted to work outside the hospital and enjoy working in the community. The FNP program worked well for me. I have many friends that are in the ACNP program currently that want to work in the hospital and they are very happy with their choice of ACNP.
As far as the job market for FNPs, it is growing daily. When I started the program 4 years ago there were many jobs posted, the numbers then dipped low and now have increased again. I have many opportunities to apply for and am excited to get started.
Good Luck with your decision and make sure to ask the instructors at the school where you are thinking about applying. Currently at the school I graduated from, the FNP program has a waiting list due to the high demand and not enough instructors.
Take Care and Follow your heart!