I’m looking at Ipads but need a “normal” sized USB output.
Are there any “Lightning-to-USB” adapters on the market?
Yes. They cost about $30. Get an "official" one rather than a knock off as Apple has done some things so the ipads can tell the difference between them.
All iPads come with a lightening to USB cable so you can plug it into your computer.
Perhaps you could be more specific in what it is you need?
I suspect you want to plug in a standard USB memory stick.
You might want to consider bluetooth solutions instead.
There are a number of drives that connect to the iPad via bluetooth.
http://www.laptopmag.com/review/wireless/seagate-wireless-plus.aspx