Throttle Bodys?

I am concidering getting a 60mm 2g TB, but the physics of this isnt really matching up, with the smaller 54mm throttle body shoudlnt you get faster flow when you are starting off the line than the bigger TB which you would get the slower flow off the line and only give higher end HP at the high speeds when you really need more air?

More flow at higher rpm, not vehicle speed. Not sure which you were refering to :) That is the rule of thumb though. Smaller intake parts will give more low rpm torque, larger is better for high rpm torque. Ultimately bigger is more power, since more torque at higher rpm is more power.