HAF XB Evo Custom Loop

[Stonyer]

Hey guys. I have had my HAF XB Evo for just over a year now and after sticking a 980 g1 in there and going to 4k I fancy making it look awesome (and hopefully cooler) with some custom watercooling, plus I am an engineer so the whole idea of building it seems like fun to me.
So far I have the following list, I just want to know if any of the more seasoned watercoolers can spot any newbie mistakes before I start buying things.

CPU: EK supremacy evo clear/nickel
GPU: EK 980 wf3 nickel + black backplate
RADS: Alphacool XT45 - 280(2 x 140) (front), 120 (rear) and 160( 2 x 80) (basement)
PUMP+RES: Koolance 452x2 Dual bay w/single D5
FANS: Corsair SP Purple LED all round (couldnt find any other purple led fans anywhere)
TUBING: EK Primochill Advanced LRT clear
FITTINGS: EK ACF compression fittings black (10/16mm)
COOLANT: Mayhems XT-1 concentrate, Ultra pure H2O 5ltr, Mayhems Deep Purple Dye.

My main questions are:
1. will the amount of rads i can fit in my case give me decent temps on my current setup (gtx 980 g1, 1500mhz + i5 4670k, 4.6ghz) and also if I add another 980 in future?
2. Is nickel a bad material to have in my loop, i want it there for the aesthetics really.
3. I have also seen that there are stainless steel plates in the res, will that cause any problems?

Any other advice would be greatly appreciated, i have been doing my research for a couple of months now and want to know pretty much everything before i jump in.

Thanks in advance guys.

 

[Disco_P]

1. I wouldn't bother with a 2x80mm rad. It really isn't going to help as the surface area is tiny. The other rads will be fine but you might struggle if you add another 980 in the future.

2. Nickel is fine. Aluminium is the metal to avoid and I don't know of any modern WC stuff that uses it.

3. Stainless steel is also fine. Again, avoid aluminium.

You also don't need to buy expensive coolant. Just Battery Water from halfords will do.

 

[Stonyer]

1. When you say struggle? You mean keeping temps in check? Surely every little bit of extra cooling I can get will help when this marginal on cooling?
Also can I just turn the fans up more to achieve better cooling, I have an h80i at the moment and those fans aren't too loud at full tilt?

2 & 3. Good to know. the reason I had picked the xt-1 was because it specifically stated it had anti-corrosive properties for use with all the metals I have in my loop (i.e nickel, brass, copper and stainless steel). Should I just go the DI with anti-growth stuff and dyes?

Just a quick thought. Could I stack an extra 120/140mm rad either on the inside of the 280 rad where there is room (there isnt room on half of it due to the gpu) or on the outside of the case behind the 120 rad or potentially both?

Thanks for the help.