T1's all the way
If you are an aggressive skier, you will want T1's. I am a smaller person too, but I do weigh more then you. I have probably gained 15 pounds in the last 15 years, so I am 140lb now. I just replaced my old worn out T1's with their new 4 buckle boot and they are definitely the ticket. The new ones are wider then the older ones, but the top still fits the same. I have no problem touring or climbing with them, I just keep the buckles loose for the uphill stuff.
If you are not sure, try both T1's and T2's on with skis and see how they flex.