Any good place to find RFC's you can recommend? When I search for them they often seem to be technical implementations of single parts of a system, instead of full system specifications.
i use my search engine of choice. Searching for "rfc archive" has some promising results. i hesitate to link to any because i don't actively use any specific one. i typically just search fir "rfc-1234" and land at the specific RFC i'm looking for. i unfortunately wouldn't know where to go to for a catalog of RFCs with an easily-browsable listing with descriptions.
> When I search for them they often seem to be technical implementations of single parts of a system,
They typically are.
> instead of full system specifications.
i'm not clear what you mean by "full system," but any full-featured piece of software may well make use of any number of RFCs, perhaps via single-purpose libraries which implement them (which is what i had in mind in my initial response).