What dashboard gauges are most useful for a slant?

I burned out the old stock temperature gauge on the dashboard of my '65 Valiant 100, And I think I just want to get a newer gauge rather than mess with restoring the inaccurate old one. Ant then I thought 'hell, as long as I'm doing that maybe I should get one of those 3 gauge clusters that mounts under the dash or something, maybe get a more accurate oil pressure gauge as well, something else maybe too'.

So if I were looking to get actually helpful gauges for my car and it's slightly rowdy 4-barrel 225 and manual 3-speed, what should I be looking at? I already have an AutoMeter tach on the dashboard that I refer to more than the speedometer. Or should I just repair/replace the factory temp gauge and call it good?