I don't think Lazio's grounds (Formello - to the north of the city) or Roma's (Trigoria - to the south of the city) will have tours. If they let in public, its usually up to the coach and I know Roma no longer lets the public in unless its an open training session or a youth match/senior team scrimmage since the coach has requested that.

As a hardcore Roma fan, I strongly urge you to buy your kids Roma jerseys or jackets or something like that. Authentic stuff too, though its not cheap. People's faces in public will light up and they'll get lots of smiles and frowns (Lazio fans). If they speak Italian, be ready for people just to walk upto them and debate/ask questions about Roma and their views.. I love it. The least they will get are looks, smiles and waves...Whatever you do, and I mean whatever, please do not buy them Juventus gear (Roma fans, and well anyone in Italy save for Juve fans), hate Juve given their cheating and scummy past.

If you're going to Naples, do yourself a favor and eat at l'antica pizzeria da Michele (near stazione central) or pizzeria di matteo (more downtown tougher to find).

In Rome take time to wander the streets and alleyways of Trastevere, as well as those in and around Campo dei fiori and the areas between piazza navona and the pantheon..

Eat gelato, lots of it, make giolitti (near the pantheon) and della palma some of your first stops.

Rome's my favorite city in the world. Enjoy it!