Well I ordered the Sanmak 13" HID. 35W version. It has a 12V 7.2AH battery. They don't have a 100W version but no problem i have a spare 100W. Hope it can go past 4 mil with ease.
They emailed me as said that the host is ready. I think BVH got quoted $300! It's $100 here + $60 shipping via EMS (6kg physical weight and 13kg volumetric, if they quoted correctly and fairly that is). It's a bit more expensive than what i would want to pay for, but then a Thor X Platinum 9" halogen host costs $48 cheapest but with shipping i think it's $125 cheapest. So this is not too bad i guess, in fact there is warranty (because i claimed once for the reflector for the SM5200 and they rushed me a replacement via DPEX in 2 days.
Damn someone ought to come out with 120W or 150W auto ballasts.
When i did a ceiling bounce test, with 24V, my 100W ballasts does about 7500L OTF. With 12V it's just under 7000L OTF. That's with these normal no-frills reflector/thick glass/Ebay Aliexpress no-frills cheapo HID bulbs. Relative to my other known lights like TK70, T40CS etc.... Not too bad huh.