I would second mcrockett's lavalier suggestion. The G3 system is the go-to system for professionals everywhere. The reciever and transmitter work from a really long distance away, are small and compact, and are very hard to break (as I found out once when someone landed on a rock with a G3 transmitter attached to their belt). They're definitely on the spendy side, but in my opinion, they're worth every penny.
As for lighting, I would definitely try a 3-point lighting set up. I think this would be the most appropriate for an interview set-up. You can find tutorials on three-point lighting all over Videomaker.com (just when you think they couldn't cover the topic any more, they bring out one more article on it), but I've linked a couple here for you to make it easier:
As for the best lighting kit, I would suggest going with LED lights if you can afford it due to their small size, efficient design, long-lasting "bulbs", and adjustable intensity. There are some great and affordable LED lighting kits on B and H Photo Video that I'd recommend. If you want to go with something much cheaper, yet proven, I would then suggest the DV55 light kit from Lowel: http://www.lowel.com/kits/DVcreator55.html. They are really inexpensive, use common light bulbs (read: inexpensive again), has a softbox light that's easy to set up, and has an extra light for backgrounds which can be very helpful. The only thing I don't like about the kits is the light stands that come with them. To me, they are way too flimsy. However, you can just buy some light stands from Photoflex or go professional and get some C-stands and you'd be set!
All the best,