If you want quality lav mic audio, the cheapest, easiest, and most worry-free solution is to plug a decent quality lav microphone into a portable recorder and have your talent wear the recorder. You then sync it in post with Pluraleyes or FCP X’s synchronize function.
I have found this system reliable enough to use on all-day documentary shoots for MTV, sometimes running audio clips 3 hours in length. The best part is that there’s no limit to the number of mics that can be run at once.
Besides your audio setup your video is also important. You may want to look at the best dslr cameras for videos to up your filmography game!