I personally would opt for a neurogeriatric doctor just because of the experience we had with my mother-in-law. I chose a geriatric family doctor for her, figuring I was getting her just the kind of care she needed. He barely looked at the records I had on her from her former doctor from another state. He stood in front of her smiling and bobbing his head, listened to her heart and lungs and examined nothing else, when I told him she had complained about her right eye bothering her, he examined her left eye, he berated me because I don't use Target pharmacy due to being disabled myself and not wanting to get her out of the car, go stand in line, and get her back to the car during Target's hours when I could go through the local drive through pharmacy any time of the day or night, and when I asked about her dementia, he was not able to confirm or assess it. He sent us instead to a neuropsychologist. I got the feeling that he liked working with the elderly because they didn't know good care from poor care!
When I switched to my own family doctor for her, he spent time actually examining her and did far more than I could even have hoped for. He adjusted her meds, showed me some things I could do for her, had me get a blood pressure cuff and calibrated it for me, and on and on. A good family doctor that you trust is, in my opinion, just fine. For more intensive evaluation of dementia, go with a specialist like a neurogeriatric or a neuropsychologist.
Maybe my experience was out of the norm. I hope so!
I wish you both the best as you try to figure out what's going on.