The Punic Wars Roman swordsman would be wear a pectroal (bronze chest piece), a bronze montefortino helm, and maybe 1 bronze greave on his left leg. That is the first line of Roman army. They are called Hastatus and use a Gladius Hispaniensis sword. The 2nd line of Roman army are the Principes and they wear the same helms, have same shields, greave, etc, but may wear lorica hamata, the chain hauberk for body armor instead of the small nearly useless pectoral.
3rd line is the veterans who are the Triarii. They have the best equipment and primary use a long hoplite spear called Hasta.
The shield have round top because that was the shape of the Roman shields in the Republic era. Round top scutum can still be found into the Imperial era, mix with square top scutum.