i currently have an mx1000 (keyboard combo was the mx3100 i think). my buttons are kinda wearing out so i was going to upgrade to another mouse (corded hopefully), but heres the thing on the mx1000 there is a 3rd thumb button that i havent been able to find on any other mice. i actually NEED that 3rd button for gaming because i have gotten so used to it. plz help me find a mouse that has that 3rd mouse thumb button and is laser and hopefully corded.and possibly a keyboard to compliment it well. thank you