new to trolling and want to buy some starter rods/reels - the local Cabelas has Okuma reel/rod combo for a decent price - but I need to know which rod action is best for trolling for crappie, these come in 7' , 7'6", or 8' lengths and Light, Med Light, Med, or Heavy action rod

So what length and action is best suited for trolling crappie, or does it really matter?