The BMPC has a 3x crop factor,not 1.7x

.........The Olympus Zuiko 9-18 maybe a choice (it became a 27-54 on FF). There is the Lumix 7-14 (21-42 FF equivalent).
The Sigma EF mount 8-16 is also valid,(24-48 FF equivalent),but requires an MFT to EF adapter.
Unfortunately these lens are not so fast........