Thank you for all of your replies. My apologies for the long delay in replying, but I was in an accident and had to have both neck and spinal surgery and am finally just recovering enough to get back into the swing of things.
We had tried a "professional" photographer, which turned out to be a disappointing and costly experience, with no usable images. We have just moved from a small town to a small city, so there are more available professional photographers. Since we need to shoot and edit 25-50 new clothing styles (front, back & closeups), 2-4 times per month, the expense of a professional photographer can run a bit high, especially while we are trying to grow our business. We do use professional models.
We were considering the Canon EF-S 17-85mm 4.0-5.6 Image Stabilizer USM Zoom Lens or the Sigma 669101 Sigma Zoom Wide Angle-Telephoto 17-70mm f/2.8-4.5 DC Macro Autofocus Lens. Any feedback about these two lenses will be appreciated. After reading the replies to this post, we now also want to look at the other lenses recommended here. I have to say, there is a genuine satisfaction in taking a photo(s) that really turns out well or the way you envisioned.
If we can find a professional photographer that is within our budget and will work with us on a regular basis and the photos are good, we will be thrilled. In the meantime, we still want to purchase an additional lens that might give us better closeups.