^ This. Your electrical should be ok. I know mine is, all stock with the exception of the big 3. You should definitely knock that out though, it helps a lot.
Just make sure you set the gains with a DMM, and set it for 900w so you don't risk anything on the subs. It'll be easier on the amp, easier on your electric, good call all around.
Also, I don't know what wiring you have ran right now for your amp, but if it's 4 gauge, you're good for now. 4 gauge is fine for the SS rubi at 2 ohms. But you will need to upgrade to 1/0 when you drop down to 1 ohm. So if you don't already have 4 gauge, just skip it and save the long run money and get 1/0. If you do have 4 gauge down, just keep in mind, you should start saving up for some 1/0.