Hi @merakian1 ,
Thanks for your interest in NXP MCU products!
For your application scenario, I recommend you to use the MIMXRT series, which provides a variety of secure boot mode, such as HAB and BEE.
In addition, after development is completed, the user can block external SWD/JTAG access by programming eFuse, effectively containing confidential code.
You can refer to these ANs for more details: 
BTW, currently all NXP and security-related documents require the customer to sign the NDA to obtain them. The specific operation needs to contact TSR on the official website.
Best regards,
Gavin