That Amazon camera bag looks nice and seems a very good deal.
I've been using a soft sided cooler for the past decade. Looks pretty much like Moke's tackle bag. It's small as a cooler but generously sized as gear bag. Currently houses a DR-680, large external battery, 6 PFAs, cabling and whatever I need to carry on top inside. Can fit the V3 in there as well if I need 8 channels, or the R44 DR680 for the few times I needed 10 channels.
I like it nice because it's lightweight for its size, fully zips up, has pockets on the front and sides, a fat well padded shoulder strap, and the internal plastic cooler tub makes the internal compartment fully watertight up to the lip. Also the removable tub makes for a hidden compartment underneath- lift out the entire tub without disturbing the recorder, batteries and all wiring to access it. I originally bought it as a stopgap solution, and as I recall it was less than $15, but it has worked so well I've never replaced it. I carry everything in there except the mic stand and/or extension arms.