A hydra 26 puts both those lights to shame. I'm guessing your looking at used a350 and radion 2 if the price is similar pick yourself up a hydra 26 hd for $349.99
Im running one of each on my tank, the big difference is the ability to control the light spectrum. It also depends on what you have in your tank for corals. My softies LOVE the kessil. The radions are over the more light thirsty corals and they love it. So.. really.. the answer is dependent on whats in your tank and whether you want to be able to pinpoint the light spectrum or not.