One of my batteries went bad so I want to buy one or two new ones, but wanted to get the best one for my set-up. I have read about the differences between "25C", "30C"....etc. and still am not sure which way to go.

My 3 battery options (all are 2s lipo)

1) ProTek R/C 2S "Supreme Power" Li-Poly 50C Hard Case Battery Pack (7.4V/5600mAh) (ROAR Approved)

2) ProTek R/C 2S "Supreme Power" Li-Poly 40C Hard Case Battery Pack (7.4V/5000mAh) (ROAR Approved)

3) ProTek R/C 2S "Supreme Power" Li-Poly 30C Hard Case Battery Pack (7.4V/3800mAh) (ROAR Approved)

I am going with ProTek because their batteries are great and I want to support Amain since they are down the road from my house

Here are my 3 set-ups. I want the perfect battery for the given set-up

1) Slash 4x4 with Velineon 3500kv brushless motor (stock)

2) Team Associated T4 stadium truck with Sidewinder ESC with 4600kv motor

3) Team Associated T4 stadium truck with Tekin RS ESC with 17.5T express duo2 motor

Any help would be great. I don't want to throw down $$$$ then wish I had gone a different way. Thanks in advance.