Questions About Micargi Stealth

Hello everyone, I am planning on building my first mb and was thinking of using a Micargi Stealth. I have been reading in the forum that there may be some problems with using this bike(Like having to take the sprocket to a machine shop and getting re-sized because of the coaster brakes.) I was wondering if I were to get the 7 speed with hand brakes would i not have to do this? Or is there a kit that I can buy that can come with the right sized sprocket? Also if there is anything else that I will need to buy along with a kit to get it up and running, please let me know. Thanks a lot in advance!