So, I've been shopping some gauges and found that there are quite a few different ranges to choose from.

Specifically I was looking at water temp gauges but I'm sure when I start looking at other gauges my guess is I'll find a similar issue.

I looked through some threads and the sticky but I couldn't find much on what range I should buy.

Should I get a gauge that goes up to 350 degrees or is 300 enough? How low should the temp show... 100, 140?

Also, if anyone has any range suggestions for the other gauges that would be great (oil press., boost, etc.)

Also, in my manual indicates that some STi models get a temp sender in the rear diff. Has anyone ever hooked up a gauge for this?