Australia import company requests: rebar

I need to purchase and export rebar to Ethiopia and kindly seeking your advice in regards to the below points, please:
1. What's the minimum amount I can buy?
2. What's the mode of payment you accept?
3. Please confirm whether your products meet Ethiopian ISO quality standards.
4. How long will the shipment takes to arrive at Djibouti port?
5. Please advice documents required to complete the export
Thanks for your assistance and look forward to hearing from you.