Depending on the ages...Nebraska Furniture Mart is right there by Cabellas too. They have EVERYTHING for a home including electronics, furnishings, decor, kitchen. Hubby and I took 3 hours to walk through...and our kids liked looking at everything and "wish listing" and they were only 3 1/2 and 18 months at the time. ... View related article.
for decorations or even dresses....EBAY!! Also you may want to check out any local Freecycle groups (freecycle.org) that may have some stuff. Also for decorations you can check out some of the party stores (especially around the new years) or even Oriantal Trading Post online. They have a ton of stuff.
For foods it depends if you want to do a buffet or not. There are a lot of sites with sample menus...you just need to do a google search.
my hubby's grandparents just had the party for their 50th this last month and their anniversary is actually in Dec. Their kids wanted to do it before the weather got bad since they are in Wyoming. ... View related article.