The 196 should talk to SkyView just fine with its NMEA output. I'm not sure we have any confirmed 196-SkyView connections, but the 296 on up are all known to work. I believe the data outputs are the same. Now, just to be clear, the 196 can be used in a few ways (simultaneously) by SkyView. One, it can be your backup position source. This gives SkyView GPS information for synthetic vision, its own mapping capabilities, and for other calculations throughout the system. In this respect it's like a backup SV-GPS-250, as you've said.
Its navigation data can also be displayed on the HSI, and can be flown by the AP. In other words, you can do a flight plan on your 196, select it as your HSI source on SV, and fly it. Note that the 196's flight plan information is not transmitted in full to SkyView, so you won't see its course on our map or flight plan.
For that last bit - to use SkyView's own self-contained navigational capability (with either the SV-GPS-250, 196, or other GPS as the raw position source), you'll need our SV-MAP-270, which is essentially our mapping product. That's a $500 one time purchase. Aviation / obstacle databases are free from our website for US customers.