Yes, it is on par to CX550 from what I see on Jonnyguru. Even a 450 will do. 1070 -> 150W, CPU -> 65W, rest -> 50 W, max draw <300W with 20% headroom, 400 good quality is enough. But 550 may allow upgrade to 1080ti or 2080ti. Decent budget choice.
Yes, it is on par to CX550 from what I see on Jonnyguru. Even a 450 will do. 1070 -> 150W, CPU -> 65W, rest -> 50 W, max draw <300W with 20% headroom, 400 good quality is enough. But 550 may allow upgrade to 1080ti or 2080ti. Decent budget choice.
CX550 is 2017 slightly better quality than CX550M, to me they are similar quality including your pick. What is the price point in your country if not US?