in terms of costs, it depends a lot on where you are, due to shipment, taxes, etc..
Thinkrider has some good offerings, low cost and seem to be positive reviews overall. There are a lot of models being continuously released, which is kind of bad since the reference changes a lot (models reviewed by GPLama for example are phased-out by now), but it's also good because it seems they're mostly improving them.
if I'm not wrong, there's a topic in here about the brand..
I have a Cycplus T2 which I've been pretty satisfied through the last 5 months. It's very silent and works really well, and although GPLama trashed it some years ago, through research I found they've released new versions and improved significantly - the model remains as 'T2' only but mine is like the 3rd version, and there's already a newer one in China.
bonus for the cycplus is that they offer a wireless control that can raise or lower the resistance. I still have to buy it to try it.
and there's Magene, which is a big brand doing a lot of stuff and seem to be doing well, but the price is normally a bit higher which is related to the brand name being more known.
regarding the zwift cog+click and everything... I've been using MyWhoosh with virtual gears for some months now and I pretty much stay in the same physical gear on all rides. I gotta reach for the mouse or keyboard to change virtual gears, but it's not that much of a hassle. And I plan to test a macropad and set it to control the gears, see if it works well for riding
it seems like a similar solution while at a much lower cost.. although I never used the zwift cog, so I don't have personal experience