In my opinion, anything more than a 14 int (maybe 16 on a drow) is too much. With a 14 starting int you can take enhancements and feats to adjust your disable and search to where you feel it should be.
I love my halfling monk/rogue and the stats were simple... 14 14 14 14 8. I will end up as a 6 monk 14 rogue and be just as good at traps as any pure rogue. Especially since the monk's fire buff gives an extra +2 to skills and I can cast it on myself if given time to meditate.
Really there's no absolute best way to do rogue, but I would say that a rogue needs to have at least 2 areas of expertise. Traps, UMD use, Melee damage. Think about those 3 aspects of the class and think of balance like the equalizer on a CD player. Try to find the balance that works for you. On my rogue/monk I wanted some fun with a Qstaff and have decent melee skills, and do traps quite well. I even have enough concentration and put the effort into using my monk buffs frequently. I sacrificed a high UMD skill, I have the ranks but not the stats, but at higher levels even my UMD will be of at least some use to the group via resurection scrolls etc.
If your concept for your character truly focuses on traps... I'd consider a build that would focus on mechanic spec for trapwork, get some good use magic device skill, and stay in the back with a repeating crossbow and wands at the ready during the heavy combat.