[Setting] Roma Fantasia

[Matthew]

Sounds good so far. You are probably going to have to put some thought into how the Roman Pantheon interacts with foreign Deities, though. Deities and Demi Gods contains the stats and portfolios for D&D versions of the Roman Gods, but I don't think it's Open Content.

As always, you are probably going to have to deal with the Light Shield / Heavy Shield / Spear / Long Spear problem (don't mistake a Tower Shield for a Scutum).

Also, Republican Legionaries are going to be wearing Mail, rather than Segmentata. Actually, having a handle on Latin couldn't hurt when running this sort of campaign.

Magic is also potentially going to be a significant problem. If you have the money, it might be worth purchasing one of the many Rome Sourcebooks available for RPGs.

How late is Late Republic for you? How close do you want the details of history to rub against the game? Caesar? Sulla?

Clerics are pretty much out, as written. There are no Templar type Warrior Monks in Ancient Rome, to the best of my knowledge, nor much in the way of a Priest Hood, in the sense of a division of society.