You are on the right track, for fuel filters they are readily available at most any auto parts store or walmart, I run Motorcraft or Nappa (usually Wix filters) but in your case anything will work for the time period. As for scan tools you will need a scanner that will read these trucks. Most plug in OBD II ones will not read anything. You will need to buy a ELM 327 OBDII adapter WIFI or Bluetooth and download Forescan (I got mine through Google play for 6 bucks or so for my phone (android). I am buy no means a tech junky (my 13 year old has to show me how to do anything on my phone or computer). But this program can read about anything these old trucks will throw at it.