The army of the Late Republic was led by a succession of generals who have made their mark on history. Julius Caesar is of course the most famous. But this is also the period of Marius and Sulla, Lucullus and Sertorius, Antony and Crassus. It is the time when the Republic's most deadly enemies were probably its own generals but it is also the time of Spartacus and Mithridates, Tigranes and Vercingetorix, Cleopatra and Surena.
I wasn't particularly interested in this period when I was buidling armies 25 years ago, but I liked the look of the new (at the time) Freikorps Romans and I ended up buying a few. The metal was pretty brittle then, but most of them survived in my possession unpainted for the next couple of decades.
These are from the Alain Touller range. They mix well with the other companies' figures. Their legionaries have pretty accurate looking shields although I'd prefer a wider variety in appearance.
I have a few of the Corvus Belli legionaries which will get painted some day. I'm not sure whether they will become the most experienced troops of a Slave army or a second Roman army for Civil War use. Either way, they are probably the most dynamic range of legionaries available for this period.