I'm completely new in the field of videography so I don't want to get in over my head with the more pro models (yet) I will be filming simple video of events around town and sit down interviews. I like that all three cameras offer ability for still photography too. All video will be going on YouTube and an online website, so I don't know how much I'll be filming in 4K. Good audio is a must, so recommendations on which would be the best for that or that offer the ability to add on wireless mics will be a plus.

The 3 cameras I am picking between are
Canon - VIXIA HF G20 32GB HD Flash Memory Camcorder - Black http://www.bestbuy.com/site/canon-vixia-hf-g20-32gb-hd-flash-memory-camcorder-black/79...?skuId=7930058

Panasonic HC-vx870k http://www.bestbuy.com/site/panasonic-hc-vx870k-4k-ultra-hd-flash-memory-camcorder-bla...?skuId=3774034

Sony Handycam AX53 4K Flash Memory Camcorder http://www.bestbuy.com/site/sony-handycam-ax53-4k-flash-memory-camcorder-black/4849001...?skuId=4849001

If someone could recommend a desktop that will handle this type of filming I'll be doing, be it Mac or windows, it would be very much appreciated.