It took me a long time to find a Wii myself, and i had to look VERY hard to get one. I found the web site wiichat.com to be helpful, and they have a thread which collects the best Wii Search Tips.
Some hints they mention.. go to itrackr.com to see what stores have it in stock, go to 'backdoor' web pages that show you if a store has it in stock or not, and show up at stores before they get delivery. (around 1030-1 usually)
Just to let you know, the online Walmart 'bundle' arrives in pieces, and you can just bring everything you don't want back to your local store. 
