We have been able to create (from scratch as well as using conversion tool) textfields, and textareas in Touch-UI but somehow not been able to make "pathbrowser" to work on Touch-UI. There is no way for author to drag and drop images from content-finder to pathbrowser.
"Create a component with Touch UI Dialog and Multifield widget. Here we extend product multifield and create a composite multifield /apps/touch-ui-multi-field-panel/multifield , configure it with two form fields, a Textfield (granite/ui/components/foundation/form/textfield), Pathbrowser (granite/ui/components/foundation/form/pathbrowser). End result is a simple Dashboard Component"
You can download package from there as well or can see demo for the same too.