Just FYI I tried this myself a while ago without much success. If you download a stock-based TWRP-flashable rom for your device and extract the contents you should be able to find the APKs for Samsung account, the store, push service etc. (some are also on apkmirror, if you want to try newer versions). The Galaxy store does actually work, but crashes when you try and go to the account page (as there's no Samsung account on the device) so you can only install free apps. The same goes for the Samsung customized versions of apps such as Kindle, it works until you try and log into a Samsung account. The actual Samsung account service itself wouldn't work for me, it appeared in the list of possible accounts to set up but would just crash if selected. Fortunately, the best Samsung app (the internet browser) can be installed on any device directly from the Play store, so you don't need any Samsung account services for it.