We are talking chinese automotive lighting equipment, which is well regarded as inferior to Korean or Japanese made lighting equipment. Generalizing 'electronics' is off topic. Philips, Osram all use Korean made bulbs in their lines. I cannot think of one household name for Chinese made lighting products for automotive use.
Plenty of seperate ignitors, even in the OEM field. Offers different packaging solutions depending on your lamp design but for retrofit kits one unit is better for ease of install. The new D1S bulb used by Porsche, Audi etc. has an igniter built on to the bulb with a seperate ballast unit. Google it and now you've seen one
Im not talking running wattage, rather amperage, specifically the startup requirements to ignite a HID bulb. Harnesses are sometimes included not for the paranoid but for the simple fact that you will fry your stock harness as its not designed for the draw required on startup of the ballasts.
Stock bulbs will draw about 4-5 amps. HID ballasts will draw 15 or higher. This will blow fuses unless changed and fry stock harnesses over time....unless a HID kit harness is used to bypass the factory parts.
My points are clearly with merit and I can provide enough data to make your head spin to prove it

But a simple google search is enough to prove my case for most potential customers.