Do i need to buy an electonic agile management system
It depends. If you have an distributed team, you surely will need something more than sticky notes. In many cases Excel is good for distributed teams. But if that does not work then you could look at an online version of tool like Scrum works, Rally, Version One, Visual Studio for team etc.
But if you have teams that are face to face or teams that are distributed but are essentially seperate teams then you do not need anything more than a physical board.
Here is a version of a manual board
You can get this by downloading this template and then go to Fed Ex Kinkos to print and get it mounted on a large board. Costs you around 80 dollars.