My radiator went pop today

Having being told that my radiator was not long for this world since I bought the car almost two years ago, she finally let go today. Nothing major, just a small crack in the top tank. Temperature was fine the whole way home, only noticed it because once I stopped the car at home, I could hear a feint hissing noise. Open the bonnet and sure enough, it’s boiled the overflow reservoir and there’s a small crack in the top tank.
Do I just buy a replacement second hand OEM one or is it worth going after market? If yes for aftermarket, what and where from?