A kernal with working hardwares is preffered
as as about the own repo is considerd its 100percent practical approach to unleash the available protential but keep in mind that would require additional maintanence but would be fine enough as you stated we can also use the official repos so no problems . we could have a fair amount of useful packages in our repo that be customised for our devices
overall this project is all about useability and the thoughts by op focus on that