Almost all wireless routers should in theory work, as long as configured correctly and their range is good enough.
The Wii supports WPA/2 which should be the very least security that you should place these days. For an additional security measure, also use a MAC filter (if router supports) and let only the MACs you identify to have access.
Also always upgrade the Router to the latest firmware, before using it, so that you are further ensuring that all is supported - for the above go here (
http://kbserver.netgear.com/products/WGT624.asp).
Regards...