I loved your response on a previous thread, (85 yo Grandma wandering around and not eating,) and it was NOT "too long." Thanks for being here and contributing.
Assuming your dad is going to be with you for a while, I suggest buying a good quality hair cutting kit and learning to cut his hair yourself. There are several reasons for doing this.
First, older "gentlemen" like a fresh cut every four to six weeks. After awhile the cost of "at home service" plus "tip" will begin to mount (and YOU will likely never be fully satisfied with the barber's "post-cut clean-up....") Finding someone (whose efforts satisfy your dad - and you,) who is willing to commit to either coming regularly (OR coming on an as-needed basis) will take time and effort. In fact, organizing these home service visits will end up taking MORE time and effort than learning to cut his hair yourself.
A haircut is a give and take process leading to a sense of "Us" or team, much like that which most mothers and daughters share early on. You and your dad can laugh together as you learn - and he instructs - a rare treat for a man in his circumstance.
A haircut is also performed with intermittent eye contact, so it will give this "loner" a chance to appreciate what you are giving him (of yourself,) while allowing him to gradually confront his own embarrassment at his dependence on your providing him with "personal" services.
So, your provision of this haircutting service could prove to be a valuable inroad toward developing trust around physical intimacy with your father, something which both you and he will need LOTS of as the degree of intimate care he requires from you increases. It is particularly embarrassing, I believe, for a man to receive certain types of assistance from a daughter, regardless of the closeness of the relationship.
The important thing is that when his needs really hit the nitty gritty, the groundwork will have been laid for an experience SHARED - one in which you can learn and laugh together, reminding each other "THIS is no HAIRCUT... but if we could get through that WE can get through ANYTHING!"
All good wishes to you and yours!