I don't think you can get a 285 25 19 My book shows they don't make it. your stock tire is 26" tall as long as you stay close to 26.tall ( 25.9 to 26.3) there is no change in your speedometer. have you done a search ?
any way here are a few tire sizes for you.
stock 255/35-19,, 10,0 wide 3.5 wall height 26.0 tall
-------255/30-20,, 10.0 wide 3.0 wall height 26.0 tall
-------265/35-19,, 10.4 w 3.7 ------------26.3 ---
-------285/30-19 ,,11.2-------3.4--------------25.7---
-------285/35-19,, 11.2-------3.9--------------26.9---
-------295/30-19,, 11.6-------3.5--------------26.0

------265/30-20,, 10.4--------3.1--------------26.3-
------255/30-20,, 10.0--------3.0--------------26.0--

jim