Can you change the lenses? If so, you need to look for a lens with macro capabilities. I was able to pick up a used lens many years ago for about US$80. The manula controls of your camera will control your depth of field. The camera lens will control how close you can get.
Depth of field is controlled by the f-stop. The smaller the opening (and thus the larger the denominator of the f-stop number) the greater the depth of field. Max this number out and you should get enough depth of field.
The other way to turn a normal SLR lens into a MACRO lens is to add macro filters to the end of your camera. I use Tiffen close up lenses on my digital camera after using them for years on my film camera. These are available in a stack of three filters and are numbered depending on magnification. If you stack all three on on top of the other, you can increase the magnification. With all three on my camera, I can get within 1" (2.54cm) of my subject.
One last trick to photographing dio's and not worrying about depth of field is to control your composition. Allow elements in the foreground to blur, this will lend depth to your image. I am always amazed how this little trick works. Shoot from under an overhang, or over another figure's shoulder at your subject.
Visit IPMS-Hawaii's April newsletter for an example of this over the shoulder composition.
Hope this helps.