Looking for a person who can weed our woods

We are looking for someone who could spray/weed 6 acres of wooded property that we own. We are not looking to do landscaping, but instead keeping the woods in their natural state and keeping them clear of certain plants, such as poison ivy, English ivy, raspberry-like bushes, multi-flora rose, kudzu, honeysuckle, and similar invasive plants. We would appreciate it if any one could recommend a reliable person or company that could periodically do this job for us.