That Italeri figure is also worth having a closer look at, thanks for the suggestion.

I'd be interested to hear what Streletz intended with the three mounted figures in this set:

http://www.plasticsoldierreview.com/Review.aspx?id=2274

As I said no.1 looks like he might be Trajan though he could just as easily be most of the Julio-Claudians. No,3 might be Hadrian or possibly Marcus Aurelius. No.2, I think, might be Marcus Aurelius or might possibly be Antoninus Pius(though you might not want him leading your legions, he thought it wiser to delegate). For want of a better figure no.2 might just pass as Septimius Severus.

I'd be up for a set of Roman personality figures, I'd like a recognisable Vespasian, my preference is for Romans in Britain, but Pompey, Octavian, Agrippa, Antony and Cleopatra would also be of interest. Also Streletz has an excellent set of Marius's Mules so a Marius and Sulla would be a fine addition.
There's plenty of interest in and figures for the punic wars so Scipio Africanus and Haninbal as well.

I wouldn't have a problem with figures from different eras being in the same box, it might even tempt me to buy some of the earlier figures that I don't have.
It has to be said that for personality sets like this Streletz is the 'go to' company, it's something they do particularly well.