Maine any bullet you'd use on a Maine moose will work for any plains game including an eland.
Zebra,eland,gemsbok are tough animals no getting around it but they are on a level with moose/elk not "caped crusaders" flying from the tops of buildings and such.
My first trip to RSA I bought a new rifle ( 300 Win mag) handloaded heavy bullets (200gr) of the finest construction,etc. and killed everything I shot at from 25 to 300 yds with 1 shot. But so did my partner with his 270 and factory loaded 140 gr bullets.....go figure????????
If you enjoy reloading and have the time it is always fun to work up "just the right load" for your safari. But like I mentioned a zebra or eland is tough but none more than a moose.
Where are you hunting and with whom?