Doing business in DR Congo (Kinshasa)

I might soon have to travel to DR Congo to do some business about some kitchens. And since I never been to Africa in my life I have a few questions I hope that some one can help me with.

General business procedure:

1. The formal dress code is black pants, white shirt, neck tie and jacket correct?
2. Are there a lot of under the table fees as standard procedures?
3. Are there some NO NO's that I should not do?

And finally does anyone have a link for a page explaining this or willing to help me?

Thank you in advance,

Michael (Living in Thailand)