Setting up a new rig!

So i have been tasked with setting up a new mining rig for a friend, he is wanting to mine ether, but he also wants to switch to siacoin, he is wanting a single rig, and will use it to mine different coins as they become profitable.

Budget of around £1500, what cards do you think would be a good option for this rig, please remember its not just ether he will mine.

thanks.