I tried something similar once, and technically, it worked. The lights were fairly dim though until I ran a dedicated power wire off the battery, and just used a relay to turn them on and off so I still used the factory switch. LEDs draw significantly less power than their halogen counterparts, so they shouldn't be an issue if you go that route. I know there are some flickering issues with them on JKs, which can be fixed easily, I just don't know the details of what exactly is affected or the cause/fix.
Either way you'll have to do some wiring as most aftermarket lights won't work with the factory plugs.