Primary Memory Vs Secondary Memory Choosing Issue ???

Hi SAP HANA Experts,

I just want to know how to choose the RAM Size & Hard disk size for the SAP HANA Database ????

Example:-

Let us think that my company is running on Oracle 11 g database with 300 GB as a database size.

So we want to migrate from Oracle to HANA Database as part of the project

As HANA Supports the compression ratio feature 1:5, so we can reduce the Original database size to 60 GB in HANA Database.

Now how much RAM we need to choose for the SAP HANA Server including the future data growth keeping in mind

& How much Secondary Memory we need to choose for this database size including the future data growth keeping in mind........