are u going retrofit HID or plug and play in your housing? that will make a big difference in actual output.
and yes, the hight Kelvin you are going for, the less output but the more color. in other words, it will look good, colorful, but you won't see shit on the road.
this might be helpful to you: Yellow:
1500 k Candlelight
2700-2900 k Yellow painted fog halogen bulbs
-------------------------------
Yellowish white:
3200 k Sunrise/sunset
3200 k Premium H7 non painted halogen bulb
3400 k 1 hour from dusk/dawn
-------------------------------
White:
4100 k Philips/Osram OEM HID D2S
5500 k Bright sunny daylight around noon
----------------
Blueish white
5500-5600 k Electronic photo flash
6000 k Philips Ultinon HID D2S
6500-7500 k Overcast sky
-----------------
Blue:
9000-12000 k Blue sky
-----------------
Purple:
28000 Northern sky
12000-30000 k Ultra Violet light (black light)

As you can see, 4100k would be right where the "sweet spot" is on that chart. It produces near to the suns same kelvin thus giving you daylight-like output. Think of it like this, high kelvin bulbs would be like being out in the sun with sunglasses on vs a 4100k being in the sun w/o glasses on.