Don't have my 250w nearby right now, but they use standard globes (DYH as I recall).
The ones that are supplied by the manufacturer with the 250w and 600w focussing models are probably not the best available in terms of QC. This probably is the reason that some folks get 25 hours out of a globe and others get 100 hours. Standard "brand name" replacements can be had at Bulbtronics or other retailers.
Hope this helps.
Ken