Originally Posted by: blowupmanAmaj7-Bmin7-C#min7-Bmin7

would that be a I-ii-iii-ii progression?

Yes, assuming A is the root and home key.

Minor chords are lower case Roman numerals, major chords upper case. Deviating from a chord built on a note of the major scale results in a "flat" chord.

C#min7 is labelled iii. If is was C minor, then it would be b(flat)iii.

If it was C# major, then it would be III.

If it was C major, then it would be b(flat)III.