Hi. I've really been enjoying birding here in Orlando, FL and am looking to invest in a new camera. For starters, I'm currently using a Canon 5D and usually use an EF 28-300mm lens while birding. Both are from 2006 and weren't purchased with birding in mind at the time. I want to go mirrorless and am not committed to Canon. I also would like a focal length of around 600mm. Any suggestions for an initial setup (body and lens) that would be around $8K or so? Thanks!