Is there a separate site/link for CDLCs developed for Rocksmith 1 and will they typically work for Rocksmith 2014?

No CDLC developed for RS 2012 will work for 2014, and sadly, there is nowhere to find any RS 2012 CDLC anymore :(

If you do find any, you can unpack it, import the XML arrangements into a new EOF project with the unconverted chart audio, re-save and get RS2014 compatible XML files. Just keep in mind that RS1 customs had extra silence put at the end of the audio and if you prefer not to have that, you would need to edit the audio to remove it, ie. with an audio editing program like Audacity. If RS1 export is still enabled in EOF, it will add silence to the end of the WAV file it creates from the chart audio.

(...) and sadly, there is nowhere to find any RS 2012 CDLC anymore :(

What about http://www.rscustom.net/dlc/ ?

It has a radio button for RS1, so it's probably as good a bet as any.