I would recommend stock first. Electric cars are affected by the set up than Nitro (at least more noticeable when learning). The cars are a lot lighter and change more with input. Mod will multiply these traits and there is more maintenance and wear and tear in mod. Start with stock and add mod later if you don't like it. Most stock guys use monster stock pro, or P2K2. There are other motors, but you won't notice th4e differences that much when starting out. Also, one cut on the comm will last you all day in stock, where mod will need more unless you choose V2.
RC Car Action Editor and Photographer