Ignore ShitSeries. Buy yourself
this. There are other great mice from Logitech such as MX Performance, MX Master, Marathon M705, G602. Marathon M705 and MX Performance aren't best suited for gaming, but on G700s, G602 and MX Master you won't notice any lag.
ShitSeries is what Beats used to be for headphones. Brand popular among gamers for no good reason. Premium price but average quality.
But it is best to go to nearby store where you can try them out for size. That is very important.
Edit: As for keyboard, no idea really. I'm using old Logitech split keyboard (for ergonomics). Have trouble using normal keyboard for typing.