Not sure if this has been solved yet. I've had success linking up the autocomplete and ListView with web api. Initially I as well couldn't get any results. In order to get it working I was required to create a Jsonp media Type formatter and change the dataType to jsonp. The paging is working in the ListView control, but I can not speak for the grid as I have not tried that yet.
So my autocomplete looks like so
The implementation for the jsonp media type formatter can be found here. I found the last post to be the easiest to implement