Getting a 1TB SSD is a little overkill if you ask me but if you wanna spend your money on that then it up to you. I would switch out your SSD's for a 500GB SSD and a 2-3 hard drive. You obviously want your Windows to be on your SSD for faster boot speeds and other programs but the majority like games and files and stuff should really be on a hard drive since there's no benefit in storing those in a SSD. You will be saving a lot of money while getting more if you go for the SSD + Hard Drive set up. Get the Western Digital Black, fantastic hard drives.
For the PSU, modular power supplies are the best to have. Easy to install and easy to upgrade. If you're intersted, you should look around for one or ask me.