R730 System Board replacements

After the warranty has expired for our R730 servers, how would I acquire system boards as an independent supporter? My understanding is that the system boards need to be "blank" and have the service tag generated upon replacement.

How do I transfer my existing iDRAC license to the replaced system board?

Is Dell the sole source for these system boards?

If I simply replace the server with a different service tag, can I transfer my purchased license to the replacement?

Thank you

Kurt