My above post has been half-solved by using the Storm Editor to add sprites and modify the .dat item properties, but using Tibia Editor 9.81 to actually ADD CIDs to the .dat file.
Thought I would mention, some sprite editing programs (Tibia Editor 9.81 specifically) will replace the last sprite with a null sprite. Is this necessary? It doesn't appear to be, since, when I don't have that null sprite by using the Storm Editor to compile my .spr file, it seems to work fine.
In your future updates of the Storm Editor, it might be beneficial to auto place a null sprite at the end (AFTER any user added sprites) when the user presses the save sprite button. Also, if the last sprite is a null sprite, theadd sprite button could add the sprite the user selects "before" the null sprite (replace the null sprite and make a new null sprite after the old one).
This addition would help avoid other sprite editor programs removing player added sprites, and it will avoid conflict if the last sprite SHOULD, in fact, be a null sprite for some reason.