Man, don't let me start on Total Realism, or Total War in general, it's a hate/love thing and I'd bore you to tears. Suffice to say that the games are great beyond measure and with mods they are even greater.
Ahem, I suggest you play Rome without mods a couple of times(and I suggest installing 1.5 pathc only after you've played as a phalanx faction, since 1.5 nerfs phalanxes thanks to a push bug) preferably patched up to 1.2 or 1.3 since the initial version has too powerful elephants and the AI is kinda crappy. Brutii is probably the easiest, with Scipii and Julii coming next, both have different difficulties and foes to face.
Brutii is, as was already mentioned, fairly rich and you can safely strumble through Greece and much of Anatolia without a worry. Phalanx isn't that hard a foe(pin them down with hastati, attacks their backs with velites) and unmodded Rome has a really impotent Macedon, historically they'd be all over you with tons of cavalry and superior pikemen. Anyways, after solving the normal campaign, just breeze through some eastern or barbarian campaign and try these mods, since anything else except the Roman factions are really unfinished in RTW, ahistoricality aside:
Rome: Total Realism - a complete rework that concentrates on gameplay and visual quality
Europa Barbarorum - a total conversion that adds a wealth of new features, superhistoricality and hardness
Hegemonia - City States a total conversion that lets you control a polis in the Persian-Peloponnnesian War
LOTR: Total War - a half finished conversion about guess what
The Crusades - another conversion, well worth waiting for
Ran no Jidai - Shogun:Total War reloaded
Blue Lotus - more like Blue Awesomeness, a fantasy total conversion with a fascinating concept
I'd totally post pictahs if anyone wants.