Well I hate to burst your bubble, I know most states, including California, it is illegal to replace your headlamp bulbs with any bulb that is a higher wattage than what came from the factory, but cops don't really care or check unless there is something that is blatently stupid you are doing and give you a fix it ticket.
As for the LED's and Hyper whites, they are both direct replacement. LED's come in all kinds of different shapes, sizes, and colors as OEM replacement bulbs, plug and play. Here is a website you can check out to research and order.
http://www.superbrightleds.com they have all kinds of LED's and accessories, check em out!!! The only thing about adding LED's is that they draw less current, which the bulb out warning (faster flash) will be on all the time if you replace them. Me I do not mind this as I can careless how fast the flash is, just make sure it is within the legal limit (yes there is a law on this too!!) which the bulb out warning is within the legal limit otherwise we would all be sold illegal vehicles There is also a plug and play fix to keep your flash at the same speed and the bulb out warning which is about $20. It's up to you, but I myself as soon as the funds are available will upgrade to LED's since they are safer than regular bulbs. The time it takes for a regular bulb to light up to its full brightness at 60mph is 15 ft. an LED to get to its full brightness is almost instantaneous. So don't you think that there would be a lot less accidents caused with LED's as standard equipment? I do. That is why I am upgrading!