I bought a cheap ELM wi-fi and dashcommand. There's a slight lag, but right now I'm only using it for fun like you seem to plan on. To be honest, when I'm really looking at it, by the time I can look over at the display it's probably caught up to what I'm doing anyway. You can check out the set up in my build link below.
and I did a DIY on putting an iPad mini in the cubby here
DIY: ipad mini magnetic install into cubby