You have of store credit. To use it, simply place your order and you will be able to choose store credit as the payment method when it comes time to pay for your order.
KangerTech Technologies has a wide range of different coil options for their tank systems. KangerTech offers Ni200 coils typically used for temperature control. If temperature control is not your thing no worries they have stainless steel and kanthal coils with Japenese Organic Cottom.