Disney shopping .com has a wedding section with some stuff. Cake severs, Toasting flutes, some figurines to b used as toppers.
I personally used a figurine I had a friend buy me from WDW.
Lennox and prescouis momments both have some disney theme items that can be used as toppers.
As for garters I bought a simple lace one with blue ribbon and sew a charm on it.
I got some cute Disney themed stuff from Wedding invite book that matched my invites.
May I suggest asking/looking on wedding board here on Dis those folks would have better ideas of what's out there now.
A 100% Disney-theme wedding was not to my liking, but I did have a Disney-inspired cake.
I had seen pictures online of the cakes you can order for your Disney Resort wedding and one was a simple white three-tier cake with the words "And Dreams Really Do Come True" written on it in beautiful silver frosting. I took a picture to my local bakery and it looked just like it. I googled "castle cake toppers" and found a beautiful one that I put on top.