If you're already going over your budget, then you can take out the SSD at no harm, but the power supply, if you want to do sli in the future, then probably leave it at 1000w. I have no idea honestly what sli for two 570's requires, 850w may even be enough.
The seagate 1tb would work with your system if you wanna keep down your budget. The SSD would just give you better boot times, game loading times, data transfer, etc. It's an upgrade worth looking into adding on in the future though.