Assuming you can convince your GM (which, if they're allowing you to take Aasimar/Tiefling and pick your personal preference for the granted SLA replacement, isn't too far of a stretch) to let you create your own custom 10-RP race, you can bump your level 1 INT even higher, by:
Greater Paragon statistics- 2 RP (+4 INT, -2 STR, -2 CHA)
Advanced Intelligence (twice)- 9 RP (+4 INT)
Slow speed- -1 RP
Can't take Advanced Intelligence, because it's an advanced trait, and by having 10 RP your race's power level is just standard. If it were a 11 RP race, it could take advanced traits.
Of course, if you had the GM's permission to build a race in the first place, they might let you ignore that restriction.