Note that i'm not a Minox user so i'll say this as an armchair specialist.
[ . . . ]
Acros 100 is finer grained than Delta 100, if you want to try it. TMax 100 is higher resolving than Delta 100. (But I love Delta 100, it gives great results).
If you do B/W slides (B/W reversal process), the grain will appear smaller and more uniform, due to the process. The Foma Reversal kit lets you do B/W slides with many B/W films like Ilford FP4, Fomapan R100 and others. And you can enlarge the slides by doing B/W reversal paper process. An inverted world. Now, i say this as an armchair specialist since i've never seen prints made by reversal B/W paper process.
[ . . . ]