Finally decided to get a PS3 for the Kingdom Hearts HD Remixes. Got 1.5 and I am quite enjoying KH 1 Final Mix. Hopefully I will get around finishing all four games before 2.8 comes out.
I already have X/X-2 HD on my PS4, and I'd say that based on the Lightning/ FFXIII Trilogy promotion going on lately, I'd say that the odds of getting the FFXIII/ Lightning Trilogy on PS4 are good.