need help figureing offsets

[viviorunitia88]

alright set up i have now 20mm wide front fenders and 30mm wide rear
have a set of do luck double six that im sending out to get barrels replaced and new offsets
rim size is 18
want 11in width for 285 tire all the way around
i have been told two diffrent sets of offsets and im just trying to figure out what excatly i need to just get a hella flush fitment without running into rubbing or turning lock to lock issues. want to try to keep even tire width since its more even for road course driving.
off sets that i have been givin already

18x11 with +25 off set all the way around
and
18x11 +20 to +15 just would like to know what on it is so i dont need to guess
18x11 +35 to +38 just would like to know what one it is so i dont need to guess

any input would be appreicated oh and this is on a fd just fyi