The dedicated 7 inch iFLYGPS 740b might be a choice. Takes the ADS-B In information from all kinds of sources, including the Stratux or FlightBox. Sold for $499 by
http://www.mypilotstore.com/mypilotstore/sep/12644
Quote: "New in the iFLY 740b
Sunlight Readability. Sunny days are no issue with the iFLY 740b and the brighter 1100 Nit 7-inch Touchscreen. Perfect for those bright open cockpits."
I myself have decided to use the iFLYGPS software (which I'm subscribed to) on the Galaxy Note8, on sale these days for under $600, with the 6.3 inch screen and up to 1200 nits brightness. What I like about the iFLYGPS app is - among many other useful features - the satellite images of all the airfields, helping to locate them if you have to land out.