I will humbly suggest you to look for "WILPU" brand long jigsaw blades; made in Germany. That brand has longer than usual blades with good quality and acceptable price. Good luck and thank you again and again for your valuable videos!
Nice idea, but 2 recommendations: - The saw blade teeth should not get in contact with the bearings. Otherwise the bearings will be damaged and the saw blade will be worn faster. Maybe use only 1 bearing on both sides? - For the 45° position the guidance by the bearings is not optimal. You will find that, when you will do a rounded cut, the blade will run out.