BO migration from BO XI R2 SP1 to BI 4.1

We are planning to migrate from BO XI R2 SP1 to 4.1

I have few questions:

1) As SAP insists, migration to higher version should be from SP2 or higher.

But in market place, I did not find BO Xi r2 SP2 & SP3. So do I need to raise SAP incident for the same?

2) Some experience people, also say that direct migration from XI r2 SP2 to 4.1 is not advisable though SAP insists.

   We need to migrate to 3.1 and then to 4.1

So it will be 2 step migration.

i.e. xi r2 SP1 --------------> xi r2 SP2--------------> xi r3.1 -------------> 4.1

3) Please guide if someone have other way to tackle this.