LEDs fail so seldom it is usually ok to just hard wire them, so no base needed, here are a few I built 2 years ago that are all still working perfect
http://spacecase0.blogspot.com/2012_04_01_archive.html the one 12V one I did set up with a standard light base had to be built, but there may be some for sale now, the LED flexible strip lighting is about half as efficient as the kinds with the switching power supplies, but they have sticky tape on the back and are super easy to install, perfect for locations where you don't leave them on for long periods at a time. or are you just looking for a fixture to put them in ? I have got neat looking regular 120V fixtures and take out the insides to use with my 12 lights and just solder the wires in