We field a lot of sales, questions and customer support for BamaChips, so you can always come to us too.
BamaChips does have some great 89 octane tunes, performance and torque, so you can certainly use those.
No need to change your plugs.
DO NOT change your thermostat out to a lower temperature. Fuel injected vehicles run best around 195 degrees.
BamaChips tuning is made to work well and reliably with all of the stock components, you will not have to change anything out just to be able to use the tunes.
For reference here is a link to the tuner: