There are different brands available on our market today for HID H4 kits. Some even offer hi-low beams too. I believe they retail it at around 25k-35k ($450-$640).
1. An HID kit is composed of 2 ballasts, 2 pairs of wiring harness for D2R or D2S bulb, 1 control box, 1 pair adapter kit to fit in the bulb housing and a pair of fusible links (take note, no relays). What you have now is just a plain headlight wiring kit for HALOGEN bulb.
2. No company has made the combination of Xenon charged bulb and a halogen charged one yet. Based from your post, you probably got the 4500K Halogen bulb that disguises like a Xenon charged or HID.
3. Xenon charged bulbs are max 35Watts only. Larger than that will not be road safe to use.
Imagine a 35W bulb with enough glare for on-coming motorists, di ba nasisilaw ka na sa 35W pa lang? What more kung dagdagan pa at gawing 50W, eh di lalo na ng nabulag sa daan. Double the 50W and you get 100W, try looking at some construction sites with flourescent bulbs that's powered by a generator set, ganun kalakas yun.
Yup, most halogen bulb brands have come out with different color/hue shades that imitate the HID color/hue. But it's the light density that a xenon gas charge bulb differentiates it from a halogen bulb.