I've been using a Topeak Joeblow for more than 10 years now. I don't exactly remember when I bought it, but I've thrown it around quite hard and it still works great today.

That said, it's not possible to have a forever-pump because all pumps have seals. These seals will slowly degrade over time. What you should look for is a company that sells spare parts and rebuild kits. Ideally a company that has been around for a long time so you can have a decent expectation that they'll still be around when you need a rebuild kit (new-old-stock doesn't work great for rubber/leather goods). Bonus points if the rebuild kit looks like parts that you could make or find from a local hardware store; just in case the company does fold.

I know Silca makes highly regarded floor pumps and they sell replacement parts for the internals. You could check them out. Boy are they expensive though.

I like park tool products. They always last for me. I've never bought their floor pump because i just have a cheap no-name one that won't die but I definitely want one for my next floor pump.

Topeak is another good brand that I like but again I don't have a floor pump of theirs just a frame pump. I've read a bunch of rave reviews for their floor pump and the guys at GMBN swear by them.

I think Silca is what you want. But I don’t know if you want to pay for it :D