Is there a Special Hadran for finishing the whole shas? or do you just recite the Hadran for the masechta just completed?
In the Artscroll gemara, it has the text of:
הדרן עלך מסכת נדה (ותלמוד בבלי) והדרך עלן. etc
So, it seems that no.
As for siyum shas mishnayot, i speak from experience that there is a special hadran, so perhaps there is for gemara as well, but just not in my sefer.