I've not been to CA Grill, so I can't help with the comparison, but at Narcoossee's there is a veranda around the restaurant that people can go out onto to watch Wishes. If the weather prohibits/deters that, then the view from the inside is really good. I gather that some of the tables at the two end of the restaurants have limited or no view, but if you can see the castle from your table, then you will be fine. When I was there in December it was very cold, so no one out was outside. As a result, there were great views from the inside. When the weather is better, I gather people go outside to watch, effectively blocking the view of those that remain inside regardless of table location.
If Wishes is at 9 pm, then I would guess an ADR for between 7:30 and 8:00 pm would probably work. The typical time estimate for a Signature is about 2 hours, so you should be somewhere approaching dessert when Wishes starts. Also, the Electric Water Pageant Parade has a stop right in front of Narcoossee's. It runs before Wishes, so if you'll probably get to see that as well.