I'm guessing mouse plus an analog device like this instead of (or in addition to) keyboard would be the best choice. Haven't seen one suited for sinister lefties though.
Sorry to revive an old thread, but as someone who has been looking for manual analog input on the left hand and used multiple of these types of devices in the past, these don't cut it because they have one fatal flaw: The thumbstick on these is not a real thumbstick. Usually the thumbstick is mapped to some keyboard inputs (like wasd or the arrow keys), so it's only mimicking an analog input without actually being one. They usually just send whatever keyboard input they are mapped to once the joystick reaches a threshold. Some of them send their inputs in pulses in increasing increments the further you push the stick, to try and simulate analog control, which works for some games and some devices, but most don't even do that. So far I haven't found a single one of these that works correctly. I have even contacted multiple manufacturers for devices I have been interested in purchasing to ask if their thumbstick registers as a proper XInput device and they always respond like they have no idea what I'm talking about.
One thing I have had real success with is the Playstation Navigation Controller
While these have a REAL analog stick, the issue is they don't make them anymore and most are completely out of stock, and they don't have any native Windows drivers so you have to fuck around with third party shit. They also don't have enough usable buttons on account of being originally designed to be the left half of a standard controller, so they only have 2 face buttons, a dpad, one trigger and 1 bumper. That might sound like a fair amount of buttons, but even in a standard FPS game you would be surprised how many buttons you actually need for things like reloading, jumping, crouching, flashlight, weapon switching, grenades, etc etc. Most modern games are made to utilise 2 bumpers, 2 triggers and 4 face buttons, and while the mouse can replace both triggers, you need to at minimum have a mouse with a few extra buttons on it to handle the few extra inputs that games expect, because you can't use the keyboard anymore.
But even the perfect device wouldn't cut it in most games because the vast majority of PC games do input switching incorrectly. The correct way to do it is to simultaneously allow inputs from all connected input devices, and provide settings in the options to only use one if that's what the player prefers (so they can move their mouse without moving their camera if they do stuff on their second screen, for instance). Instead, most games try to be "smart" and only enable whatever input device last sent input, which completely breaks devices like the Steam controller and this PS Navi controller setup because the moment you move the mouse your analog movement will stop (and vice versa).
I personally hope for a future where we can get proper analog support on PC alongside a mouse, it really shouldn't be that hard, but nobody seems interested in it at all, so there aren't any devices for it and most games don't work properly with it. It's a shame, really.
