see this ithink this bulb will get full light or 99% of the light
bulb

Long arc = bad. Color temperature = bad. Do some forum reading and you'll understand.

its a cool idea if they made a mh like that ( with built in reflector i mean )

Generally, you would want the arc of the bulb to be short as possible down to a point not long and thin. HPS bulbs are known to be as low as 2000 (k)elvin in brightness color temperature which has an orange to redish tint which would discolor your lcd's color pallet tremendously on projection. The lowest I've seen used and appeared acceptable was 4000k. If your looking to use HPS type bulb then Retro White models like the Phillip Ceramic 400w should do you which btw has a shorter arc.

BTW, color temp differences between 6500k and 4000k to look at.