I can't speak to sheet film, but in 35mm, Fomapan 100 is most like Agfa APX100 in terms of grain and overall "feel." Note that this is largely a subjective view, but it's one that others have expressed, as well. The Foma product, though, has poor anti-halation characteristics in 35mm (I believe larger formats are better in this respect).
T-grain films (Kodak T-Max, Ilford Delta, and Fuji Acros) are an entirely different kettle of fish, as they say, with a very different look to them and finer grain -- although I doubt if you'd be able to see the grain in Fomapan 100 in sheet film unless you made mural-sized enlargements.
Concerning developers, I believe I've used D-76 and
DS-12 developers with Fomapan 100. I've not shot a lot of the film, but based on my limited tests, the DS-12 produced some subjectively very appealing tonality -- or maybe it was just good subjects for the film. My experience is limited (just a few rolls), so I can't rule out happenstance in such judgements.