The 970 is designed for 1440p, so it's somewhat overkill for 1080p. It should run a single monitor at 144Hz at 1080p. So a single 980 or 2-way 970 is probably over-kill. As for the 295x2, that's for 4k really. It's waaay overkill and it's also a ridiculously hot card. Don't do 3-way or 4-way SLI...ever. It causes micro-stutter in games and it's extremely annoying. For £500 I would do either SLI Zotac 970s or a single 980.