Any Logic Board for a specific model will work as they have the same physical layout. The A1707 is not specific enough for a designation. You need the exact model found by clicking the Apple menu and selecting "About This Mac". However, this is not something Apple or an Apple Authorized Service Provider will do for you. Plus, if the laptop becomes locked (firmware password, or Activation Lock), then you will end up with a brick since you won't have the necessary paperwork to have Apple to remove the lock.
Besides the 2017 model has a lot of known design issues especially with the Butterfly keyboard. You would be better just using an external USB3 SSD for storing your data. The other option would be to purchase another laptop with enough memory & storage for your needs.