What type/specification would I need to pump water from a well/tank to another tanks (header) approx 300m in distance with an elevation of around 30m.

A very big one. US length almost 1000 ft. and 95 ft. elevation. Depends on volume needed and pressure. Here is 1 link

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=6&cad=rja&uact=8&ved=0CDwQFjAF&url=http%3A%2F%2Finspectapedia.com%2Fwater%2FWell_ Pump_Capacities.htm&ei=0yr6VK5xyJ0254SAsA4&usg=AFQjCNEbpTJVzbicy0zUnp-R5OWIBTUPsQ&sig2=AEupSD2V9DfCg-bSYfcEzQ