At the moment this Firefox shell browser is just available as a preview version in a small number of countries and a limited number of beta testers that signed up (a thousand?).

https://www.mozilla.org/en-US/firefox/ios/ https://support.mozilla.org/en-US/kb/install-firefox-your-ipad-iphone-or-ipod

So is there an ETA?

And what can you suggest as good possible options in the meantime? (In my searches i've come across many including the native safari, mercury, dolphin, foxbrowser, etc... it's a bit overwhelming...)

something to make the experience coming from desktop firefox browsers as smooth and seamless as possible, you know?

Firefox for iOS is more of a shell as it does not use the familiar Gecko and JavaScript engines that the desktop and Android Firefox versions use.

The iOS Firefox was made available to Canadian store back about Sept 22 so it may be in US sometime soon.