It will depend on what lures you want to throw & what lb braid you want to use
6-10kg will be great for 20lb braid ( you can expect a finer tip section - which should make the outfit nice to throw the lighter weights - Frogs , 5 inch hollow bellies , 110 slick rigs ..... & smaller profile twitch baits like X Raps (10s & 12s) , smaller bombers , stiffy twitch baits , & smaller B52s
8-15kg would be good for throwing the heavier plastics - 6" Storms , Power Mullets , 130 slick rigs & the bigger diving HB's like Classics , Barra baits etc .
Chris