Help me to build my u4/3 system

Depends on how much you want to spend and what focal lengths you need.

A reasonably comprehensive system would be:

Olympus 9-18 (cheaper) or Pana 7-14 (more expensive) or Olympus 12/2 -- wideangle

Panasonic 25/1.4 (more expensive) or Panasonic 20/1.7 (cheaper) or Sigma 30/2.8 + 19/2.8 (cheapest)

Olympus 45/1.8 (great portrait lens)

Panasonic 100-300 or Olympus 40-150 (depends on how much reach you want)