Fomapan 400 in 35mm is on Tri-Acetate, 120 roll film is on (Blue) Polyester. iso 400 you can only reach in Diafine which is in fact a push developer.
Fomapan T200 is about iso 125-160, same base but a mixture between Hexagonal and Cubical crystals which gives the film a very special look.
Fomapan 100 is a real iso 100 film, same base, nice film and it will fit with a lot of different developers. IMO together with the T200 their best film. For push development the T200 will do better.