From what I've read Suleiman would be suited to Four traits:
Creative
(massive culturall accomplishements under his rule, "Some of Suleiman's verses have become Turkish proverbs", also a vast amount of laws etc.)
Industrious
(Large scale building "Sinan became responsbile for over three hundred monuments through the empire")
Imperislaistic
(Inlargered empire, Ottomans reached their venith under him, respected even in the west.)
Expansive
(see above)
Personally i think the best trats for Suleiman would be expansive/Creative (which was fearsome in Cyrus's hands in civ 4), given the great extent of cultural deveolpment and vast expansion of the borders.
Justinian should (in my opinon), be Imp/Ind, since he tried to rebuild the Roman empire, solidified law from a state into a empire (justinian code) etc. and he ordered the rebuilding of a third of Constantinople after the Nica riots, along with new buildings and construction across the empire, and the Hagia Sophia.