New Guy looking for brushless / Revo info

Hello,

I am building a brand new electric Revo.. I just got a hold of a brand new Revo 3.3 roller. Am I better just converting the existing chassis to electric since it is the 3.3 exteneded chassis? Or should I go ahead with the GorillaMaxx chassis, which I believe is the shorter 2.5 chassis?

Also, my local hobby shop has a Hacker C50 motor and Quark 125 ESC that they are trying to sell me. I am a very smooth driver in stadium truck indoor... what I am NOT looking for is the fastest motor. I run Open Truck, I'm used to that, but what I am looking for is A LOT of Slow and Mid Throttle control. I do not want a setup that works, full throttle and brake. I use a lot of slow and mid-throttle in my driving and need a combo that can give me the Precision that I am looking for. Any suggestions?

Any info would be appreciated. Thanks.