Film choice is very subjective.The OP wants something slow and fine. Gigabit when tested is extraordinarily sharp and grain free, but needs its own dedicated developer. Adox 25 (which I've tried) is good, but the grain is no finer than PanF. As for PanF itself, it is just beautiful. Rate it at 25 ISO, use a dilute developer to control contrast and it will give rich shadows and lush highlights.
I use it in 120 format, where it is as good as FP4 in 5x4 (Heresy!). I've shot both, on the same subject, back to back, and prefered the PanF. If Ilford would make in in sheet film I'd never buy anything else.
Of course, I started of by saying it was subjective. I've heard some people say Delta 100 is just as 'sharp' as PanF, and it's faster. I've tried it and just didn't see any magic. So, is Talisker better than Glenlivet, or Highland Park? Everyone has their own favourite in everything.
PS- Yes, Delta 25 got scratched. Too close to PanF, and too likely to simply cause existing users to switch rather than generate new sales and new revenue. Which was probably true.