4 3.7v cells is what you need. You decide if you want to get decent ones or these ones. Generally the range for 3.7v cells is around 3.2v - 4.2v, meaning if you have 4 of them in series, the voltage range will be around 12.8v to 16.8v, depending on how charged they are.
No, that stuff is for 3.7v battery packs, you need a pcb + charger for a 14.8v battery pack. That holder holds 4 cells yes, but they are wired in parallel, which multiplies the capacity x4, not the voltage. Your cells will need to be wired in series.