Nice one mate. Just goin with the mrs
You're probably better off with a hotel then. Can't help there I'm afraid.
Was also wandering about getting around, dont wanna hire a car taxis expensive? tour busses an option?
The best way to get around is walking. Nearly everything worth seeing, (The Trevi Fountain, the Coliseum, the Vatican, the Pantheon, the Forum) are all close to eachother because they would have been contained within walls hundreds of years ago. The walk from the Vatican to the Coliseum for example shouldn't take more than 25/30 mins and goes through some beautiful piazzas. The Coliseum to the Trevi or Partheon would be less iirc. Taxis are knocking around but I only used them when a bit drunk and there are buses (tiny ones) that service all parts of the city. But, again, I think the best way to experience Rome is to walk through it.
BTW, if you're planning to see the Vatican make sure your wife covers her shoulders and wears something that goes below her knees. They will make her wear stupid papery things to cover up anything they don't like on show. Something all the women in our party were very angry about, but it is their country.
Tour buses to other areas around Rome are available on a dialy basis. We went to see Pompeii one day on a bus that left in the morning from close to the Coliseum, I think. The tourist information office will help you there. If your planning to stay in the city don't bother with a car, the drivers are mental, it's not just a cliche. If your planning on visting sites outside there are plenty of day trips available.
If you plan to go, enjoy mate. It's like no city I've ever been in. Weather permitting.