The best options are (more or less in order), the new JW Speaker 8790 adaptive headlight, then the Vision X Vortex (or Custom Dynamics Trubeam, same thing afaik) 7-inch, then the JW Speaker 8700 Evo 2, then the Truck-lite Phase 7. They are also arranged more or less on cost, the adaptive is awesome but very expensive, the Vortex and 8700 are very good and $400-ish (I'd probably get the Vortex, and I currently have the 8700 evo 2... it's great but I think the Vortex edges it out, especially if you get the attachment that fires up both low and high beam when you go to high beam) and the Phase 7 can be had under $200.
These are all 10 minute installation jobs, maybe less. Open the headlight bucket, remove the reflector from the trim ring (held in place with some tension clips), put the LED reflector in, replace the clips, put the ring back on the bike. Plus, they're all DOT approved and road legal.
Oh, and the little light inside the original housing is a normal "wedge" style bulb, I believe, much like the license plate light in the rear. It only comes into play when you put the keyswitch into park mode, so pretty unimportant almost all the time.
See also:
Comparison of 12 separate 7-inch LED headlight reflectors.