Greenfield sizing recommendations for HANA

Hi We are planning for a greenfield implementation of the following systems on HANA:

ECC

BW

SCM

PI/PO

GTS

Here are my questions:

1. In terms of Cost of licensing and use cases, do you recommend we choose traditional oracle database over HANA for any of these systems?

2. We ran quick-sizer and the results didn't make a whole lot of sense. Can you suggest a starting point in HANA sizing in terms of the RAM to begin with? (We are thinking of 1TB RAM for ECC on HANA, 512 GB of RAM for BW on HANA)

Thanks!

Veera