What is the difference between a athena big bore and athena race kit?

I have an 01 yz125 that has had the cylinder fixed twice. I dont want to have that cylinder fixed anymore. I was thinking athena, but my problem is that i dont know the difference betwee the big bore or just the factory race. I mean i know what a big bore is and what it does but what do the athena std bore kit add to you bike.Do the race kit keep the power the same and just add more topend speed. And also do the 144cc big bore add more bttm to mid and lose on topend or does topend stay the same. And which would you guys and gals choose. Also i heard that the 144cc has bttm but no rev is this tru. Help is grately appreciated.