A Furry Peanut :
Also, I need one that doesn't require wi-fi so I can connect the two devices anywhere without the need for internet data.
You do realize that you can use WiFi WITHOUT USING INTERNET right? It's called an Ad-Hoc network and it's very easy to set one up (http
/stateoftech.net/how-to-use-wi-fi-on-canon-70d)
Just know that you can't have high quality preview doing that, and even HDMI output won't be good. You need a 7DMKII or 5DMKIII for best results with an external monitor.