Comments. 400 watts ius a bright light, the only reason I can think for going for that is that you want to grow bright SPS corals. If not, frankly you're wasting electricity. If you do go for the 400, try to get an electronic ballast else your ballast will chew a few hundred watts on top of that. If you're tank is more than 3 feet long try 2 times 250 instead.
2. Your sump sounds ok, but more light.
3. Stronger return pump, put it on a manifold 'spray bar'. Assuming you're going SPS try to get a pump rated at least 1000 per hour. I have 10 times an hour, and am now definitely looking to upgrade.
4. That skimmer seems to be consistently rated as bad. It simply isn't that good at producing foam, never mind noise/reliability. Do more internet searches before you buy stuff.
5. You're already looking at calcium dosing. If you a 400 halide, you'll likely want an autotopoff, so maybe you can does kalk with that.