So it sounds like you ‘need a servo’ because you want to be able to control the position with an RC remote?
You’re right that the system will be a servo, but what you don’t want here is a standard hobby servo like something from ServoCity, HiTech, etc, that’s what I assumed you were asking for.
IMHO steppers are the easiest electrically because they won’t require any position measurement (like a potentiometer), but a wiper motor is likely the cheaper choice.
Since James presumably has all the code published, it shouldn’t be too difficult, the harder part is probably coming up with the mechanics to rotate the device, you won’t ever really find a motor you can straight up attach to an axle and spin the thing around on. It will probably require some sort of pulleys, gears, etc.
Edit: I’m pretty sure I know where this is going and I can’t wait to see it.