I don't trust oil change places to do anything. Also I don't think flushing the trans in a old vehicle is a good idea. Just do a drain and refill with a new filter on the trans. Flushing the cooling system is a pain, but I don't think it's worth the cost of having someone do it.
Also flush/replace the brake fluid, just be careful not to let the master cylinder run dry in the process or you'll have a heck of a time getting the air out of the ABS system. Flush the power steering system and refill with Mercon V. If you want to cheat, you can use a turkey baster (or transfer pump) to drain the P/S reservoir and refill it, but you'll need to do it at least 3 times to get most of the fluid changed.
You'll need a transfer pump (under $10) to do the front diff fluid because there's no drain plug and you can't get the front cover off w/out pulling the diff. If you have LSD in the rear you'll need the Ford friction modifier for the rear diff.
Brake fluid - DOT 3
Trans and P/S fluid - Mercon V
Diff fluid 75/140 full synthetic gear oil & Ford LSD additive in the rear (if LSD)
Transfer case Dex/Merc ATF
Trans filter Motorcraft or WIX
Engine oil filter Motorcraft (or better)
Engine oil Ford synthetic blend (or Mobil 1 full synthetic) 5W30
Spark plugs - Motorcraft double platinum or iridium (gap = .054)
Plug wires - Motorcraft
PCV valve - Motorcraft
Thermostat - Motorcraft
Other things you should plan on checking/doing:
Upper/Lower front ball joints, because the OE grease boots rot away
Front sway bar end links, because the bushings rot away and they also tend to break
Check your metal brake line (especially in the rear) for rust
Hoses and serpentine belt
Mysterious coolant leaks are typically caused by the plastic thermostat housing on the SOHC V6 which requires replacement.