Implement 1503 - SP03 (1511) , which needs netweaver 7.5.You can implement the latest Sfin 1503(1511) version ,BUT you also get Slog ... So you have the latest version and the latest 1511 apps, but you also have Slog which makes the SRM config unworkable.
I think you are mixing up two products here (I use the current product names since April 2016):
- S4/HANA Finance 1503 SPS 1511
- S/4HANA Enterprise Management on premise edition 1511
The first is not based on / does not need NW 7.5 and does not contain sLog.