A range of colors that work well are DMC floss numbers #838, #839, #840, and #841. If you only need three floss colors, drop #838. If the original design calls for five flesh tones, you can add DMC #938 for the darkest tone.
When substituting the cheek colors, choose from the DMC range of #632, #3772, #407, #3773, and #950. The cheek colors you choose will depend on the intensity of the flesh tones around the cheek. You wouldn't want to have the darkest cheek color to be darker than the flesh tone used next to it. The easiest way to choose is to lay the skeins of flesh colors you are using in order from dark to light. Then choose the cheek color from the range given that is closest in intensity to the lightest flesh color and try using it as your darkest cheek color. In most instances, this method will work fine for choosing correct cheek tones.
For hair color substitutions, the DMC range of #844, #645, #646, #647, and #648 works well with the flesh and cheek colors mentioned earlier. The DMC colors #645 and #646 are close in intensity, so you will probably need to use only one of them.