All grade 8 from ACE Hardware for the bellhousing and tranny. Speed shop or Mancini for flywheel bolts. Make sure that the flywheel bolts don't go through the crank and rub the block. If you have to, grind then a little shorter.
Make sure that the bolts don't bottom out before pulling the trans in tight. Check the hole depth with a nail then compare the bolt engagement, if it's not the same, clean out those threads with a tap. Use the longest bolts possible without bottoming.