I would say, for best light quality (and quantity) without any concerns for light cutoff differences and glare, go with an H9 bulb (clear bulb). They are easily modded (on the bulb socket) to fit with the H11 halogen enclosures. The only concern will be bulb life but they will be less expensive compared to silverstars. I would pass on silverstars as I haven't had a set that has lasted (plenty of Google results for problems with silverstars).
As for LEDs, I did take some interest in the LMZ (essentially Philips Lumileds bulbs found on eBay - there are 2 variants, 2 emitter vs 4 emitters). While the concept is intriguing with the ability to rotate 360 degrees within the enclosure and up to 4mm of fore/aft adjustment, I'm not 100% convinced that it will be perfect. After playing with so many LED bulbs and looking at the variations in the beam pattern against a garage door (from a close distance) and lots of night driving (thanks to daylight savings time), the ideal concentration of light should be in the upper band (top 15-25% of the beam?) to provide light at a distance while the remainder of the beam (everything below that top band) should be progressively less and less light to provide an even light for medium to short distance. [I'm not discussing the light spill above the cutoff aka squirrel finders but that is important as well for lighting up signs as I'm still gathering data] With that in mind, when you observe the pictures of the LMZ/Philips in the Morimoto projectors, you will see a very intense but even light spread for much of the beam, which will likely equate to a large amount of foreground light (where the same amount of light is hitting something that is closer will appear much brighter than the same light hitting something further).
If you do decide to take the leap (even if you go through eBay), I would suggest orienting the LEDs such that they emit light horizontally (where the circuit board is perpendicular to the ground) as I have found that with they make the best use of the internal reflector in order to give the maximum light through the projectors. This will likely give you plenty of light in the upper band as well as side-to-side illumination.
Be conscious that the 6000K color of most LEDs (or even aftermarket HIDs) may reduce the contrast of the objects being lit (at least from the eye's perspective)... while this isn't a safety concern per se, the human eye does have less blue receptors in the eyes, so visual acuity may be impacted. [I'm not an expert in this area, but definitely an observation while testing all the different styles of LED bulbs.]
Lastly, through all the testing, I do believe there may be something out there (eventually) that can utilize the H11 projector well enough to make it a viable headlight. Now only if I can talk to someone about prototyping a set that I have an idea for
Good luck!
*I'm no expert in all this... but all of the above is derived from experimentation and personal experience.
*edit: all this talk of the Philips... I just might jump on a pair for curiosity-sake... decisions decisions...
