Look for one that comes with a person that doesn't need to ask, would be my suggestion - especially if your company is planning on spending a lot of money here, on these ads or in getting these brochures printed.Common Law of Business Balance
:"It's unwise to pay too much, but it's worse to pay too little. When you pay too much, you lose a little money - that is all. When you pay too little, you sometimes lose everything, because the thing you bought was incapable of doing the thing it was bought to do."
I can't disagree with this, you're showcasing your products, you owe it to yourself to have them shown off in the finest way possible, buying a camera and trying to shoot them yourself is a poor alternative to getting a pro in, they'll take care of colour accuracy, lighting, perspective etc, all of which take a long time to learn
I bet you'll find your sales figures increase sufficiently by having top quality photos of your products to offset the cost of having them photographed.