Empty spot in pannel

I wanted to ask the experts before I buy , I have built my pannel wiring is
almost complete.. very close, I have a dynon d-180 efis/ems both in one
mostly because thats all I could afford, anyway the question is,
presently I am adding True airspeed , Altimeter , manual Rpm Gauge, and a navaid autopilot I know its old technology, but thats all I could afford and I still need to pay the guy.. but I have one more 3 1/8 hole and was planning on a rate of climb , dynon is top centered , airspeed is top left
altimeter is top right , rpm is bottom row right below the airspeed, the navaid is on the bottom left, garmin 496 in a gizmo bracket above the icom a-200
garmin 320a and softcom st intercom.. (pain to wire) anway if anyone has
any suggestions for the bottom middle 3 1/8 these are for back up mostly but you never know, one day I plan to replace the navaid head with a trio so its wired for it.. Day / Night VFR, although
I don't plan on ever flying at night but could happen if I ever learn to fly..
creativeair wingtip lights, strobes and led nav and vans tail strobe anyway
suggestions before I buy something that I don't need.. the dynon will
have everything but but then again I built it so anything could happen..

any suggestions.. ?

Danny...

Just think about how many planes are flying with Tach, Oil, Altimeter, Airspeed, T&C, a comm and maybe a transponder and that's IT. No GPS...no AI, no DG and certainly no backup. It's totally not a big deal, even at night if you have some stars and a town or two.

Personally, If I were VFR only, I would yank every steam gauge out of the panel. Even if you did that, you'd still have backup altitude, and more importantly terrain avoidance, from the 496...also ground track (even better than heading, IMHO). Plus you have the Navaid to keep you level. If you got rid of EVERYTHING except the 496 running on batteries(not legal but if your whole plane shut down, for example), you'd still be in fantastic shape. Upside is that you're lighter, cheaper and simpler.

If you're worried about total electrical failure, it's probably cheaper and lighter to buy Dynon's backup battery if I had to guess. It's also probably more reliable than any mechanical gauge you might put in there....not enough hard data yet to say for sure...let's talk in 20 years

It's not what you asked but it is a different perspective on the whole thing.