www.wysiwygwebbuilder.com

Wondering how to go about getting an editable combo box, can't find it.

Not to mention I would love to find a checkbox listbox.

Thanks

Set the combobox/select type to 'datalist' to make the input editable.

Datalist (HTML5). A datalist is a combination between a combobox and an editbox. The user can select data from a list or enter the value manually.

Unfortunately, there is no standard checkbox listbox in HTML.
But you can implement it with third party scripts:
https://codepen.io/shawnlknight/pen/mepwYz