XL-H1a wirless mic set up

Recently I began using this beauty of a camera to video college football and baseball games. I would like to have the capability to record audio on the sideline/dugout while recording video from 400+ feet away. I believe a couple of issues must be addressed here. First of all, powering the on board receiver. I assume that an adapter and pancake or brick from Anton-Bauer would be in order. What I do not know is abundant, but includes the integration of a receiver with the camera and power supply. Also, there is just so much real estate on the posterior end of this camera where an adapter/external power supply and receiver connected to the XLR inputs would reside. Then of course, there is the issue of choosing the best combination of mic/transmitter/receiver for this application. BTW, I am not planning on mic-ing up a given individual, but rather picking up the sounds of the action as well as chatter etc. by the coaches and players. It would be nice to have a 2 mic set up though with one as a lavalier in case we decided to do both on separate tracks. I have quite a bit of experience with the video end of the canon XL cameras, but virtually none with modifications of stock audio input/recording. Thanks in advance for your thoughts and suggestions.