Rogue Leader :
Wattage wasn't your problem, and more wattage won't make you "futureproof".
RM series is all good. The current CXM models are ok. If you can afford better you should.
The Corsair RM650x is more than enough for your needs.
My Old CM Thunder 600 is starting with it's fan and then making a loops of restart again and again with countinous beeps, i have tested with corsair vs 450 which work fine
What used to happen was My PC was getting shut down automatically after few minutes ,now it is making a loop of restart every time i switch it on ,After testing it with other smps i got to know it works with other smps,So just wanted a high quality smps, But the CM smps starts to run it's fan and then stop and start again,so i am not 100% sure if it is dead or completely faulty
Just wanted more power as i may upgrade to other GFX in future as the smps will last for 10year