We have a MID YEAR OFFER right now (USD $50 OFF) on the new LifThor Sif COLLAPSIBLE tablet holder as a COMBO kit that that includes the tablet holder, video feel cable, lanyard, carrying bag and the sunshade.
I tried a bunch of different options from Amazon, Polar Pro, etc. MavMount 3.0 is absolutely what you want. It's not the cheapest, but it is hands down the best. Extremely well made and clearly a pro-level item.