So if wanting to do sealed, you would, with that driver, need a DSP to do a linkwitz transform in order to help flatten out and crossover at 80Hz with the sub. You cap out at 23W due to X-max and 103dB at 1m. You get the benefits of sealed with great performance.
https://www.minidsp.com/applications/advanced-tools/linkwitz-transform
Now this is to allow the lower extension on the driver at the cost of a bit of SPL. It is worth it. You then put on a low-pass and high-pass filter to constrain the woofer and then apply any PEQ to the driver needed to correct for anything that popped up. Remember, always drop sensitivity. Raising sensitivity can cause the driver to reach compression early.
So, from the source, before amplification, you go to the DSP, then to the amp. Since you are doing a custom speaker, you will have to customize the crossover point to your drivers for best results, which you can do with one off speakers. This would call for a DATS v3 and a calibration mic like the umik-1.
https://www.parts-express.com/Dayton-Audio-DATS-V3-Computer-Based-Audio-Component-Test-System-390-807
https://www.parts-express.com/miniDSP-UMIK-1-Omni-directional-USB-Measurement-Calibrated-Microphone-230-332?quantity=1
So there goes another $250, but well worth it.
The DSP can allow you to dial in the speaker in real time, fixing it, testing, and just iterate until it is as good as it will get or your patience allows.