1. For K1:
- I-485: K1 as Principal Applicant and K2 as Dependent.
- I-864: K1 as Principal Applicant and K2 as Family Member
- I-944: K1 as Principal Applicant and K2 as Household Member
2. For K2:
- I-485: K2 as Derivative Applicant and K1 as Principal Applicant
- I-864: K2 as Principal Applicant and K1 as Family Member
- I-944: K2 as Principal Applicant and K1 as Household Member
Base on my experience with 2 rejections and taximan683's experience, this could be the correct thing to do currently.