Shockwave was one of the ones I've always wanted as a kid but never been able to get. Good luck on finding it! I recently found a G1 Blaster at my parents' place and was ecstatic (only to later misplace it somewhere in my house), so I know you will be as well.
Nice find, Dann. I remember Top Spin very well as part of my childhood. Here's someone's pic of the pair of Jumpstarters: