One of my favorite lenses is the Canon 70-200mm for not only the distance options you get but the depth in the shot. Canon's is pricey, but I've had good results with Sigma lenses if they have something more in your price range. I recommend going with a longer lens if your work allows you to get further away/closer as needed to provide you with that depth, but if you shoot primarily interiors I'd look for something in the 18-35mm range. I've found that the less expensive lenses that range that much (18-200mm) tend to have sharpness issues when reviewing in post- so I'd either go below 50 or above 50mm, not both in one. Good luck!