Batteries, Batteries, Batteries

I have some basic battery questions for all of you professionals. My batteries are the basic stick packs. I am using the EPIC 3000 mah packs for like $19 at towerhobbies. If I want to upgrade since I am going to start racing in the stock class do I need to get batteries that are side by side? Is there a benefit to those? I don't know how to make my own packs so I was looking at maxamps and some other sites that will make them for you. Second question, when does it become necessary to start discharging, cycling etc. If I am racing for fun in the stock class (I have an evader st pro with a p2k2 motor) is it a must to get this extra equipment? Or is it more of a modified racer that needs the extra speed etc. I was told when racing like I am, you don't even need to discharge nimh packs because they don't have a memory. Is this correct? And lastly, with my circumstances, is matched cells that much better than unmatched cells.

Thanks in advance,
Chris