Do you have smooth play in 45 FPS? If you do, you dont need to upgrade anything IMO. I play with 60-70 FPS and game runs pretty well and smooth...in some heavy missions, FPS drops to 40-50, but even then my DCS is running well.
Almost every settings on "max".
i7 6820 HK, 16 GB DDR4 RAM, 1070 8 GB, 480GB ADATA GAMMIX SSD.