Minisforum ms-01 + TrueNAS + external DAS = Good NAS?

[Enquiries]

I would like to make my own NAS/cloud utilizing my Minisforum MS-01 with TrueNAS OS. Im not sure the best route on how to add storage to the device. Should I just use what is available internally (2 8TB NVME with 2.5" 8TB) or can I add some type of DAS (Terramaster U5 Hybrid)/external enclosure to expand my options.

Thank you in advance for your help. Please help me save sleepless nights and wasted money.

Cheers,
Elliot