glennj3,
Thanks for posting the pictures. The arms on your stand may not be long enough to reach the back side of the block mounting holes with the clutch and pressure plate in place.
I would remove those for sure. If you are doing a full tear down for rebuilding, the flywheel will eventually need to be removed anyway. Better to remove it before mounting it to your stand as the stand will definitely get in the way later.
The length of the bolts needed must span the length of the arm bolt sleeves PLUS enough for full thread depth engagement into the bell housing mounting holes and as you noted must match the diameter and thread count for the existing holes.
DO NOT use unknown or un-rated/un-graded quality bolts. They will be carrying a bunch of suspended weight and need to be good known quality products. Others will probably chime in on what minimum "Grade" of bolt is recommended.
Dan
