@cadxdr@weirder.earth yeah, you can even download the schematics and build one on a breadboard if you really want! (all the essential components for an arduino uno come in through-hole packages with .1" pin spacing, though you don't get USB with that)
Some of the third-party ones may have some modifications to the circuit, but all in all it's a very simple circuit--with the exception of the USB to serial stuff it's not far off the bare datasheet recommendations for the ATmega328P
-F
@cadxdr@weirder.earth the only thing I'd worry about is if you were going for an arduino uno or mega2560 or something and you got a clone that had the connectors slightly in the wrong places, so you couldn't properly use the "shield" boards designed to go on top of it, or just poor quality connectors that don't make good contact or something--but it would be trivial to replace them even if you have no experience soldering and only have a $5 hardware-store soldering iron
-F