AFAIK, there aren't any regulated mods that go above 200W, if you're looking for more, the Hammer of God might be the way to go. It's a 4 battery parallel-series unregulated mod. Bit big, but you need it to be to get the power you're looking for.
Bear in mind however, that because it's series, it's likely that your current build won't work. I'm guessing it's around 0.15 ohms? With a series box (8.4V max), you'd be pushing up to 470 watts at 56A, which is 28A per battery - doable with some LG HB2's and taking into account voltage drop, but still very much pushing the limits of safe. Personally I wouldn't dip below 0.2-0.25 ohms (with VTC4's, 25R's, or HE2's) if you went for that setup, without further testing with a multimeter to work out the voltage drop/internal resistance.
edit: Supreme is up and running! Pair of kanthal fused claptons, 6 wraps, 0.5mm cores wrapped in 0.2mm, angled because they wouldn't fit. Vaping beautifully at up to 150W, though I like 100W.