What API can I use to get FAA NOTAMS or will this one I found work?
As @GdD mentioned in the comments, there is an API for NOTAMs here: https://www.icao.int/safety/iStars/Pages/notams.aspx

You also asked for metars, which you can get from here:
http://tgftp.nws.noaa.gov/data/observations/metar/cycles/${TIME}Z.TXT where ${TIME} is the hour of the Zulu time you are interest in, wrapped between 0 and 23 (eg. 16)