Hi Dreamer--
I have never heard of a HST Whiz Kid before. I googled it and came up with this web site where it is for sale.
http://www.justitdist.com/brandys5.htm
Essentially it is just a tiny ruler that you are going to lay diagonally across a square of fabric and mark the stitching line for a HST. In actuality, any ruler will work, just make sure you are placing it correctly for your markings.
The 2" Squar-Um is just a square ruler with a diagonal line marked on it. The diagonal line will help you make sure that your HST block is correct before you trim. Any 2 1/2" square with a diagonal marking on it will do for you.
Here is a link to the 2 " Squar-Um
http://secure.netsolhost.com/87062.8...tegory_Code=RU
Are these supplies you need for a class??