"EV/EBITA, with its incorporation of balance sheet, would seem more sensible as a screening/selection tool. But I have yet to find an easy data source for this."

That sounds like one of the criteria in the "magic formula" described in the __The Little Book That Beats The Market__.

I am working on a screening tool for the ASX and NZX using these principles. The data IS out there, eg on Yahoo finance - it's just a question of aggregating it, and that's not actually hard to do.