It is best to reshape a SAWZALL blade to fit your jigsaw. Takes a little elbow grease and a file or grinder if you have one. It helps to bend an kink in the tab to help the blade stay in the jigsaw.
Get a 6" one that is wide like this to help keep the cut straight. Any brand will do...
![](http://www.homedepot.com/catalog/productImages/400/ae/aec2de79-5f61-4dd7-89ca-5f4b911809b4_400.jpg)