"S" sized motor vs "L" sized motor

[Metallover]

I am trying to choose a motor for my budget crt .5 conversion and I need to know the pros and cons of each size of motor. The motors I am looking at are similar to fiegaos in performance, probably a little greater. Here is a link to the motors - "L" "S"

The L motor is 300kv more then the S sized motor, and along with the size difference it will obviously be faster. The S sized motor is 50mm and the L is 60mm. I want to run 3s and about 4000mah and I want to hit 40-45mph.(although more is always better)

The questions I have is what kind of performance difference will there be between the two and what kind of runtime differences will I see. This is a budget project and I think I will need a $30 100a esc for the L which is rated for about 90a and I could use a $20 70a esc for the S which is rated for 60a. The 10 dollars I save could be used on a bigger lipo or go towards something else.

Right now I am leaning toward the L sized motor, but my opinion could change. I know all of you will say save up and get a medusa or Neu, but I just want something that works and is cost efficient. I can always upgrade in the future. I have owned a couple Neus for my vendetta and recoil and I know how insaine they are.