...preferably something that requires me to upgrade too often also at least support of 16GB or 32GB if upgrade is needed.
For what it's worth...I don't think any current Apple notebook sold supports 32 gig of ram (16gig max).
As far as upgrading later. Pretty much no worries here.

During the past couple years Apple has greatly reduced the ability of the end-user to upgrade Apple notebook computers. Traditionally...pretty much all an end-user could upgrade on an Apple notebook computer was the ram and the storage (hard drive).
Practically all Apple notebook computers now have the ram soldered onto the logic board (NOT upgradeable later by the end user). So all ram that will EVER be needed...needs to be configured at the time of purchase.
As far as storage upgrades. Practically all Apple notebook computers currently being sold have flash storage (no spinning hard drives). Apple intends for the storage on new Apple notebooks NOT to be upgradeable by the end-user. So again...all storage that an Apple notebook computer will ever need...needs to be configured at the time of purchase.
But...technically speaking...upgrading the storage on newer Apple notebook computers is possible (OWC/macsales.com does sell upgrades). Ram is 100% NOT upgradable after purchase.
So as you can see. It is best to configure the computer with as much ram & storage at the time of purchase as you will need in the future...and can afford right now.
Upgrading is really not a problem.

Apple has mostly taken this option away from us (unfortunately)!
- Nick