This is scope creep!! Haha, You could create a function that takes in the index and material you want and set them to variables. Then call that function when you make the widget.
Modifiy the code here to use those new variables.
You can also adjust your texture array to be a struct with the index and material.
As for the on-click widget that should show.. doesn’t look like there is anything unique. Although there could be by repeating the process in that blueprint.