Absolute BEST viewing spot for Wishes? Right smack where the "Partners" statue (of Walt and Mickey) lies. :D
But I jest. As to where to stand for the best view? Last I was there in February, I found dead center in front of Cinderella Castle to be a great spot, standing right on the curb. In my case, I had a rehab wall to lean up against, so I got LOTS of amazing pictures, most of which are posted online at my fotopic.net site. Here's a great one I took from that trip for an example:
(Taken with 1/13 sec shutter at f/2.8 on a Canon Powershot A70)
The main problem is that I had to stake out that spot for about an hour or so during the off-season; imagine what it may be like on the 4th!
However, I will say one thing, both in regards to the fireworks and to your honeymoon. There's nothing like the light of the castle reflecting off the face of someone you love, and this location WILL take your breath away. :)