Maybe this help someone save a bit if you intrested for both devices or sell rest and keep only one. It's working out as follow:
Surface book i5/256/8gb - £1189
Surface pro 4 i5/256/8gb - £721
Xbox 1s 500gb + Fifa 2016 - £249
Basicly if you add 1 xbox for 249 you get 249 off from other device (no need to add 2nd xbox, 249 OFF its added instead of 2nd Xbox...) That's on top of 10% off. Possibly 8.8% quidco cashback on each surface + 16.50 for Xbox (confirmed with quidco..)
Still "overpriced" but best deal around i suppose if you want invest and resell rest...
To get it you need
Add surface book, add 1x xbox, then add surface pro 4 and skip adding 2nd xbox...