The LAH crew figures Brian mentions are wearing the one-piece camouflaged panzer overalls, which were certainly worn for Zitadelle, but I think you would be better off for Normandy using figures wearing the standard Panzer uniform, & painting them in the SS "pea-pattern" camo. This suit was more prevalent by then.
The overalls were definitely worn by Stug crews in 7th & 8th companies of SS Panzerregiment 9 (Hohenstaufen division) at least, & probably by the other companies as well, judging from photos taken at the funeral of the CO Obersturmbannfuhrer Meyer, but not necessarily by the Panther crews in other divisions.
As regards ranks, the commander would normally be an NCO (SS - Oberscharfuhreer, Scharfuhrer or Unterscharfuhrer). The driver & gunner may well be an SS-Sturmann or Rottenfuhrer. The loader & radioman were usually SS-Schutze.
In a platoon leaders tank, the commander would either be a junior officer (SS-Untersturmfuher or Obersturmfurher) or a senior NCO (eg SS-Hauptsturmfuhrer). If you really want to ring the changes, he could be an officer cadet (SS-Junker, Oberjunker or StandartenOberjunker, these ranks corresponding to the senior NCO ranks in insignia with the addition of two cross stripes of NCO braid at the root of the shoulder strap). The gunner & driver may then be NCOs.
Since the uniforms worn were camouflaged, the special low visibilty rank markings are used (green stripes on black). There was no marking made for ranks below Unterscharfuhrer, so it seems these either didn't bother wearing anything, or used their service dress insignia. It seems shoulder straps from the service dress, black with pink piping & NCO "tresse", were commonly worn on both the camo clothing mentioned above, against regulations.
"Lord Raglan wishes the cavalry to advance rapidly to the front, follow the enemy, and try to prevent the enemy carrying away the guns. Troops of Horse Artillery may accompany. French cavalry is on your left. Immediate. Airey."
for hopefully some answers.
