i am looking for bulbs ect for a new project i am starting and found a few suppliers.
one is lampspecs.co.uk who have the best online selection i found so far.

eye mt400dl

# MT400 DL/BUD
# 400 Watt, CCT 6500K CRI Ra 90 Vertical
# Clear, operates on Mercury control gear
# GES E40 Giant Screw Cap, 12000 Hours Life 32000 lumens

there 400w 4200k range of metal halide

400w 4200k

i am unsure which to go for but continuing my research.

also waiting for a call back from Iwasaki EYE