I have a Rough country 6 inch lift kit and love it. They offer an excellent warranty and went over and beyond for me when i ruined a part with my own stupidity during install.
35 inch tires are what is recommended with the 6 inch lift. Get the steering stabilizer for it as well, it helps.
Make sure you have extra money set aside when doing this, you never know what you may find needs replacing in the front end while your doing all this.
94 fullsize blazer, rockwells, bigblock, th400, and np205
2001 GMC Sierra- 8" lift 37" tires
2004 Saab 93turbo Linear
2011 toyota rav4
99 Honda shadow 1100
2004 Kawasaki Mean Streak 1600
2011 Kia Soul! - Fiance's