Well the the questions about the mic I'll try to answer. But first I have to ask you a few questions: What are you planning on recording the audio to, the camera, a digital stand alone recorder? What camera are you using?
In most cases it is best to record sound separately to a digital recorder. I believe that only the 5D2 allows you to control your audio input levels on the camera, but there is no way to monitor what you are getting. That's where the stand alone recorder like a Zoom H4N comes in. And it will record better audio than the camera anyway. But they cost money. They can be had used to keep the price down.
Then comes the mic. The first thing I ask a client before placing a mic on anyone is what is the look you want? Meaning do you want an exposed lav mic, hidden lav or a boom mic overhead? Same question for you.
If it's a lav mic (small mic pinned to the shirt) you want, then there are a couple of ways to do that. One, like you mentioned above was to do a lav mic via a wireless system. The other is to have a hardwired mic running back to your recorder. But that means a wire and less mobility, but it is cheaper than a wireless system. The problem with a wireless system is that they aren't cheap. There are some out there that will get the job done, but are not the the best sounding systems. Clean, quiet wireless audio is not cheap. But there are cheaper systems available. Used systems are also a possibility. Try www.trewaudio.com
look at the consignment section under Wireless. I was just looking at that stuff today and they had some nice, older Lectrosonics systems that would fit into your budget. Look at the Lectro 185 systems. They are good, rugged systems that professionals still use today. They have a couple priced at $200 Canadian at their Toronto store. A good used Lectro M-150 mic should cost you about $100. So for right around $300 plus shipping you'll have a very decent wireless set up. But call them up at the Nashville store and talk to them about what they have and can do for your budget. They may have something new in stock that isn't too expensive.
Lights... I know about them, but that's not my gig. I stopped being a grip years ago. Any decent audio guy worth his/her salt doesn't touch lights, stands or sand bags unless it's their own stuff. 