Don't know about Wishes, but I have a 5 cd box set "Classic Disney" 60 years of Musical Magic that I got at Wallyworld and it has 125 tracks total and Fantasmic, Main Street Electrical Parade, The Tiki Tiki Tiki Room, and some other songs that are in the rides, like "Heffalumps and Woozles". It does say distributed in Australia, but I was very much in Virginia when I got it. Also, the "Disney's Happiest Celebration on Earth" has ride songs on it too.
On Itunes, check the podcasts and you can get the "Wishes" fireworks video on the Dis Video podcasts listing. I watch that all the time so I don't get Disney DTs.
As for the Castle, search on allposters.net with "Disney World" and there are 3 different ones of Cinderella castle...when I tried "cinderella castle" that didn't work
The music is on cds for sale all around the different stores located in WDW. As far as a good picture of Cinderella's Castle. you may want to post this question on the photography board. I have a few pictures, but would not consider them print worthy. We are getting prepared for our next trip and I will have my new camera in tow. If I get a great picture of the castle, I would be happy to share it with you after we return. If wanting something sooner, post your request on the photography board. There are a LOT of experienced photographers there and I am sure someone would be willing to help out.