Go HID.
You get 3 times as much light as a 55 Watt halogen bulb for just 35 Watt.
Chinese HID replacement sets can be had as cheap as about $25 including shipping, that is for a complete set with bulbs and ballasts (like
this one and
this)
I replaced the halogens in my (projector) low beams because I could hardly see at night, and got overlooked by other road users too
HIDs took care of that, and the pattern was perfect.
I would
not recommend using HIDs for low beams in reflector housings designed for halogen. High beams though - all the way
Apparently a
H9 bulb is a H11 style lamp with a slightly modificated connector. The difference is the slightly higher power use (65 Watt) and light output.
See
Difference between H9 and H11 bulbs?
That said, a H11 HID set should outperform any halogen H9 set with ease.
Many 'H11' sets do not have connectors at all; they come with 2 metal pins that need to be plugged into the (female) H11 connectors of the car. The H9 to H11 conversion should be quite easy on that one
If you go with a loose pin set mind that they are +/- dependent.
Check which end is + with a volt meter or simply swap the pins if the light won't shine.
As with halogens, never touch the glass. Clean with paper and pure alcohol if in doubt.
There are HID kits in any color.
Mine are 5000K which means white with a slight hint of yellow (much whiter than halogen tho).
6000K is most common, which is white with a hint of blue.
8000K are distinctly blueish, above that verges to purplish and attracts the attention of the law.
I've seen 3500K, which are much like halogens, just 3 times as bright - or 5 times if you go with 55W HIDs (which seems like overkill to me).