Here is the new Primaris Company Champion which is an exclusive limited edition model that is only available at certain tournaments and wargaming conventions. You'll probably have to buy it on eBay or something to get one.

Here is the classic Company Champion which comes in the old Company Command box which includes a Captain/Chapter Master and his retinue, and the new one which replaces the old Captain/Chapter Master model with the Shadow Captain Solaq model which used to be an exclusive model introduced as a Raven Guard Captain.