Boot Camp is NOT efficient. Having to reboot into another OS is pretty much the opposite of efficient if you're trying to get work done. It's fine for games, but completely useless for dealing with one app during the workday.
QuackBooks is not compatible with Wine (It's classified as "Garbage" for every release after 2008:
https://appdb.winehq.org/objectManager.php?sClass=application&iId=120).
QuackBooks for Mac is actually a much better program than the Windoze version, but it's missing some features, and at this point it's unclear if Intuit is still going to be supporting it long term. And if you're having to interact with QB users on Windoze on a regular basis, it's a pain to move your files between versions, since they couldn't even be bothered using a common file format.
And yeah, 4GB is barely functional for any OS, including current Windoze. It's much more stable and faster with at least 8GB, and with a 16GB Mac, that doesn't really leave enough RAM for your real software.