Prok can fruit alone, but it still benefits from a partner. Many persimmons can fruit alone, but a second compatible persimmon often improves consistency and fruit fill. It flowers in mid bloom, which is worth knowing if you add a second tree later. Usually grown in USDA zones 5-9.
No single variety stands out as the obvious partner, but that is not a problem here: Meader, Prairie Star, Szukis, and Yates all bloom close enough to work. Pick whichever your nursery actually carries. If you plant more than one persimmon, keep them close enough for bees to work both trees during bloom. In home plantings, about 50 feet or less is a good target.
One thing to keep in mind. American and Asian persimmons are best matched within their own group.
To put that into practice: at a minimum, one self-fruitful persimmon can work, but two compatible persimmons usually give you steadier crops. Better still, plant two compatible persimmons from the same group, such as two Asian or two American cultivars, for better fruit set and more backup. If you already planted one self-fruitful persimmon, add a second compatible cultivar only if you want stronger yield and a better buffer against weak bloom years.