For day-to-day use the stock guages will handle all of your driving needs. Everything else is basically eye candy though they can help diagnose problems.

Transmission temp - useless IMO. You aren't towing anything.
Fuel pressure - you would need four of them . And the problems are in the injectors more than the IP.
Oil temp - generally not an issue.
Coolent temp - er, isn't this stock?

What would be nice to add is vacuum and intake manifold pressure. Actually I would have two vacuums - one at the pump on one after regulation. Vacuum is an ongoing problem with older vehicles.

EGT would be interesting but if you are in an unmodified system its usefullness is probably minimal.

What I am considering are adding indicator lights: Overboost protection, A/C compressor clutch, electric cooling fan, and kick down switch. The usefullness is probably minimal (except for the overboost) but it may make some pretty blinkenlights.