I would encourage you to use the RBA section. Building your own is fun, cheaper and should result in a better vape. The kit comes with pre-made 0.5 ohm coils, so initially you won't even need to wrap them, just instal and wick.
The main advantage of using the RBA section (apart from a better vape IMO) is that once it gets gunged up, you can remove the wicking, dry burn the gunk off the coil and then rewick it . The coil in mine is 4 months old and still going strong. Another advantage is being able to build the coil resistance that best suits you rather than the two premade options. I found the sweet spot to be around 0.8 ohms.