Can you suggest/recommend any resources?
For buttons I recommend Sanwa, 6x30mm primary buttons + 24mm start and select buttons. They even go around in bundles with a joystick for cheap (
example) and they already have all the extra bullshit that you need like the joystick restrictor plate, etc., although do check in the auction if internal cords are included too because those you might have to buy separately. But what's interesting is that you can actually build an arcade stick with additional 4 buttons on the left that will function as a joystick. I played one of those made by my friend and it's surprisingly accurate for fighting games. Still, if you want a joystick then look for Hayabusa, Sanwa, or Saimitsu. These generally come highly recommended.
You also need a controller board + button and joystick cables and a USB cable. I can't recall any specific manufacturers so I guess it doesn't matter as long as it supports the platform that you want to play on. Although
here's a neat little kit that you can use, I vaguely remember using a similar board.
The trickiest part is the shell for the stick. Building one yourself is the hardest option, but it's also the cheapest and you can make it out of anything you want and make it as ergonomic for your hands as possible. Or idk, just make it look cool. I already mentioned repurposing PS3 fat's case and you can get that by grabbing a bricked PS3 for dirt cheap and just gutting the insides and drilling holes for buttons and cables. With the right tools it's really easy. If you don't want to bother with any of that, though, there's like a bunch of cheap arcade stick shells that you can buy on Amazon or Ebay, whatever design floats your boat, as long as it matches your stick/button setup.
Anyway, obviously this will require more effort than just buying a manufactured stick, but it's a fun little project and it's really satisfying to make something like that yourself that's truly one of a kind. Good luck!