I have 2 of the same lights and the newer lights are more expensive but the penetration is much better and the overall performance is obviously better but you pay for it. In a tent that is that small the two are going to do you just fine. I would roll with what you have and see how it works and go from there. Those little lights will surprise you,they are workhorses. As far as the lights blowing up with water,if they do then something went real bad. Most hps lights come with a glass cover but there should never be water anywhere near there. Hps are high pressure gasses that put extreme heat out. The thing that will make those pop will be if you get oils from your hands on them when switching bulbs.I personally wouldn't upgrade for the size of that tent it would be wasted money in my opinion.