[s4i]

> a rootless C maj 7 is equivalent to an E min 7.

You mean just the regular E minor (triad)?

Anyway, there'a quite a lot of stuff on this site apart from this cheat sheet page: the chord page does indeed include inversions, e.g.: https://muted.io/c-major-chord/

[makeset]

Jazz sheets often write 7 assuming it may be played as 9, if not 11/13 even. A triad in the left hand being a bit too pedestrian, a rootless “Cmaj7” is virtually always played as a rootless Cmaj9 (EGBD), or more commonly a rootless C69 (EGAD) especially if the tonic. Inversions may include the root instead of a 9th, e.g. BCEG.