I really like 18 front and 19 rear. A 245/40/18 on a 8" wheel up front is 25.7" on a 18" rim, so 7.7" bigger then the rim, a 275 / 35 19 on a 9.5 is 26.6 tall, 7.6 bigger then the rim (we call that equal) so both the front and rear wheels have the same amount if tire around the rim, but you get 1" of wheels and tire stagger. Also,, i think the 26.6 tire fills the wheels well nicer then a 25.6 tire does.
JMO
here is a good example
BilletSpecialties
Bonspeed
Boze
Forgeline
HRE
iForged
Rocket
Rushforth