After re-reading this thread, couple things:
- 4300K is the temp recommended by experts (XD for example) because this temp yields the most lumens. After all, you're upgrading for better lighting, right? Now, if you're after "the look", higher temp ratings will appear whiter/bluer to the eye, albeit at lower lumens.
- As to headlight adjustment, you really should check this after installing HID. If you'll use the search feature I cited at the thread beginning, for something like "headlight adjustment", or "headlight aiming", you'll find how-tos. Our 4Rs sit high and you'll scorch eyeballs in that Corolla's RV mirror.