I'm an angler and instead of downplaying my boat I downplayed my electronics haha, so bought a new boat, no electronics, I transfered my 798 ci SI to my new boat, and am looking at a 798c SI, will this work with my AS interlink box I got?

Yes, INTERLINK was not discontinued until the XX9 models.

Thank you so much.

What map cards can I use for both stated units? Upstate Ny, erie, Champlain, 1000 island Oneida etc.

The best for you is either Navionics or Lakemaster and the one that has the coverage you need.

 

You can download the lake list for Lakemaster from their site and you can view the current Navionics maps on their website's Web App.