Challenges in migrating from BEx WAD to Design Studio?

Hi ,

I am new to Design Studio and client is willing to migrate their BEx WAD reports to one of BO Tools. But they are new to Business Objects. They dont have any setup for BO.

Could you please suggest me on the following as i need to suggest them on these.

1. Why Design Studio is the best option to migrate from BEx WAD ?
2. What are the challenges or risks in migrating BEx WAD reports to Design Studio applications?
3. What would be the landscape setup for Design Studio?
4. What would be the license cost if my client is going for Design Studio?
5. what are the known issues in migrating from WAD to Design Studio?

Thanks

RK