Need Help with Gears Please

I have a 2009 Tacoma double cab SR5 and adding a 6inch lift and 35s for tires on it. I was wondering if 4.56 gears would help me on better gas or would going to 4.88 be a better choice? I have heard many different choice in both but want advice from toyota owners not sales people. I also heard if you get 4.88 you also had to change out something else the drive shaft or something cant really remember what they said before. I was wondering what anyone recommends I should do and what gear size to choose for better performance and gas mileage and also if it was to be 4.88 if I had to change something out as well or is it just the gears I can put in. Thanks and hope can get some help out of this.