I have recently taken an interest in wildlife photography and need a new lens. My budget is $1,800. I bring my camera on hikes usually mounted right to my chest or waist so I don't want a fuckhuge 600mm. I shoot with a Sony A7RII. Any suggestions? I am considering this below but would like 400mm if possible since I have the extra budget for it.
https://www.amazon.com/Sony-70-300mm-SEL70300G-F4-5-5-6-Lens/dp/B01DLMD7DK/