Nice. I have two of those XFX Black Edition cards coming next week sometime (probably Friday). Overpriced but the backplate could come in handy jammed in side by side for a miner. You should be good with your RM1000 provided you keep the the voltages in check. Yes please remove any unnecessary HDD's and underclock your CPU, RAM, and disable any third party controllers in the BIOS (Firewire, extra USB 3.0, Sound, SATA controllers). This will save you additional watts.
Don't worry about ASIC ratings so much. Keep your eye on default voltages for each card and tweak accordingly. Sometimes cards with lower ASIC rating will have better memory making up any speed or power advantage a higher ASIC rated card will have. I've also noticed (in general) higher ASIC rated cards, like the ones in the 80's consume more power by default than lower ASIC rated cards. Maybe for gaming the higher ASIC rated cards have an advantage, but for mining they don't appear to.
Also note you're a little unbalanced with your 290 GPU/Memory speed ratio. You need to watch the GPU memory usage while mining (for some reason you have this monitoring disabled?). Anyways, at 1030Mhz core you shouldn't need to set your memory any higher than 1125Mhz. This will lower your wattage a little more. The goal is to get your memory usage to roughly 95% but watch your hashing output to ensure you're not negatively impacting performance. Hynix memory works a little different than Elpedia etc.