eBay in Europe was a dead end for anything recommended on this forum.
Try this one:
https://www.ebay.es/str/qoppacollectables
I don't do much eBay, but I know that guy and he's a bit of a hub of darkroom equipment. There's someone doing something similar in Germany as well, but I don't know his name. Plenty of other, smaller-scale sellers, too. The UK is also an option, but evidently less attractive these days if you purchase from mainland Europe due to taxes.
However, I recognize what you say. The user base of this forum and much of the advice offered is heavily US-biased. Most of the time, that's not necessarily a problem, but when it comes to sourcing certain products and materials, you hit a dead end while the European ecosystem has plenty of alternatives to offer. To give a simple example: if you were to look for a 4x5"color enlarger in the US, you'd most likely end up with a Beseler or maybe a DeVere. In Europe, it'll be a Durst 95% of the time. If you keep searching for a Beseler 45MXT in Portugal, you may have to keep searching for 3 years until something ridiculously priced even pops up, while you could get a Durst L1200 next week.
So the main advice would be to "translate" the American advice into a European context and look for common equivalents to what Americans suggest.
The biggest local classifieds websites also had nothing. Facebook Marketplace? None. Amazon.de and Amazon.es, which ship to Portugal, don’t have these items either.
I imagine Portugal is a bit of a difficult place in particular due to its 20th century history, which did not favor (to say the least) an amateur darkroom ecosystem. You'll have to source from other European countries, most likely. So for large stuff like enlargers and big easels, shipping costs will be a factor, or you may have to engage in some multi-purpose roadtripping...
It's different in other places; sites like leboncoin (France) etc. will have plenty of offerings, but Portugal is kind of specific due to geographic location and recent history.
Instead of Amazon, focus on local classifieds websites in countries like Spain and France. Ask around where other people find their stuff. Local thrift stores may be your best bet, but you'll have to let go of shopping lists and be creative with what you can find instead of looking for specific items.