Thanks for your reply!
I will likely make 1 step per month or so (I'd like one step to be fully dry before moving on to the next). The initial steps I will practice with are single steps to the shed and side door (back of the house) which are not very visible. If I dare, I would do some steps in the front of the house, these are larger but only 4 of them so I have the luxury to dismantle and pour one at a time a allow them to dry fully before moving on to the next.
Those mixers seem cheap, if they are better than my drill I would not mind getting one.
Finally, I can buy a concrete mixer (something not fully pro but I believe enough for this project) and then sell it after the project to recover some of the money as I can't imagine I would to tons of concrete work after this. (wife already approved that idea since contracting to do these steps is SUPER expensive)