So the dash display is basically a computer monitor in my car that displays whatever I plug into it, what do I need for it to show gauges?  

 This is where the versatility comes into play:

•  You can utilize a tablet with tunerstudio or shadow dash to mirror to the dash display via HDMI cable.You can display gauges and tune right on the dash. 

Pros: Often cheap if you already have a tablet.

Cons: You will need to manually initialize the software every time and set your screen to mirror. The touch screen is not friendly for tuning. Battery life of the tablet may be a concern.

• You can utilize a mini pc with tunerstudio to mirror to the dash display via HDMI cable. You can display gauges and tune right on the dash.

Pros: Often cheap if you already have a laptop, convenience of mouse and keypad on laptop.

Cons: You will need to manually initialize the software every time and set your screen to mirror. Relying on laptop battery life for your dash.

• The best option is you can use a Raspberry PI with TSDASH software that allows you to run the gauges independently.

Pros:  The dash display will boot up with your gauges automatically when the ignition is turned on.. The PI runs off your car battery.  You can connect with a laptop wirelessly to the PI simultaneously with the gauges running and tune in the background.  You can tune right on dash display by switching it from TSDash to Tunerstudio. You can even trigger and look at datalogs.

Cons: Costly, intricate and a little complicated with not that good of documentation.

You’re getting excited, but wondering what’s capable of such a setup?

• With the full paid version of Tunerstudio you can create your own gauge layouts with as many variations and designs of gauges that you can imagine.
• You can connect a GPS and design a layout to display estimated power, mpg and performance.
• If your technically savvy you can create apps on the PI that can be displayed, the TSDash Software runs on PIos.