P.S. To any Limeys or any English speakers who were educated in English by Limeys: In the US, we keep the first floor on the first floor. You know, the first floor one steps onto when entering the house. The English apparently have moved the first- floor to the second floor for reasons unknown. I do not know if the next floor above is the third floor or the second floor in the UK. And I have no idea what they call the first floor..... maybe the pre- first floor? The first floor B.C.? The upper basement?
We call the one at Ground level, the Ground floor, the one above it the 1st floor, then 2nd floor, etc.
If you live in a house in which the "Ground floor" is raised off the ground, then chances are you are not in the UK, or your house is in a high flood risk area.
In the USA, most of your houses are on posts or stilts, so are raised off the ground with a crawlspace underneath most of them. If building with wood this makes sense, but if building with brick it doesn't. In the UK, wood houses are rare, brick is common.
I guess it all comes down to the locally available building materials and how you build. :-)
W.r.t. LED vs HID, I prefer the LEDs.
The biggest problem with HID in H4 form is that it requires a physical movement of the bulb, normally via a solenoid, to switch from low to high beam and in my experience this is what breaks first.
LEDs have zero moving parts, so long as you don't go for the 3GigaWatt 10Million Lumens versions that require fans to cool them.
The H4 LED in my C10 has lasted 5 years/40k miles/2 crashes so far and still works perfectly.
Yes, it does have an external box, but it's smaller than the HID ballast box it replaced and gives off less heat than the HID ballast box.
Cooling is passive with a large heatsink but there is plenty of room for that on the C10.
The one fitted to my C10 is nearly identical to this but being older has the external box as well.
https://www.superbrightleds.com/moreinfo/miniature-and-subminiature-bulbs/h4-led-fanless-headlight-conversion-kit-with-compact-heat-sink-4000-lumensset/3929/8565/My C14 still has the OEM bulbs as I find that the light pattern is excellent and the brightness is more than adequate for my use.
I do have 2 LED 10W spots mounted on top of the mirrors that only come on with high beam.
I bought a set of LEDs for it but have never gotten round to fitting them.