Tazling

Complete n00b to eGPU here. I am considering what seems to be a common dilemma: build a gaming Hackintosh or hang an eGPU on my 2013 21.5" iMac. The iMac has an NVIDIA GeForce GT 750M 1GB graphics card. It is just dandy for every application except gaming. The only game I play seriously is Euro Truck Simulator (the Mac port is solid) and I'm finding the 1GB memory on the NVIDIA card is starting to hurt, I'm losing framerate in areas with many textures and objects. So... tempted to beef up my system a bit. The gpu on these later "slender" iMacs is soldered in, so no hope there. Therefore, choices... build a dedicated gaming Hackintosh or add an eGPU to the iMac? I already use a second (ultra wide) monitor for gaming so the fact that the eGPU can only drive an external monitor is not a problem for me. Switching "primary monitor" back and forth is something I do all the time :-) Losing visible boot loader screen is only a minor issue for me; I don't run dual-boot, and if I needed to do a diagnostic or recovery boot I would just disconnect the eGPU. So I'm leaning towards an Akitio + NVIDIA card eGPU. It seems simpler and cheaper. But I'm puzzling over the dc power requirements. I read about people successfully running NVIDIA 970's in the Akitio box (heavily modded with brute force!), but when I read the specs on the card at NVIDIA's web site it claims this card requires 400W! When I read the specs at Tom's Hardware it says that the 970 in gaming mode pulls more like 200W. I understand (I think) that to power such a hungry card one must supply external 12vdc, the little Akitio P/S is nowhere near up to the task. But elsewhere I read that it's not recommended to pump more than 120W into a gpu card in the Akitio box... so I'm hopelessly confused now. Who to believe??? I believe the person who has really done it :-) Please could someone who has *successfully* configured an El Capitan Mac to use a 970 or similar (3+GB vram) NVIDIA card as an eGPU in an Akitio box share their actual hardware shopping list? and explain how many molex connectors they used to deliver 12vdc from an external PS to the gpu card? I'm comfortable with the soldering and so on, just worried about buying the wrong stuff (it may be cheaper than building a Hackintosh from scratch but it still ain't exactly cheap). This is my first foray into video card hacking (I don't count installing NVIDIA's web-drivers which is a no brainer), so please be patient with my enormous ignorance... PS I have been looking hopefully at the Gigabyte GeForce GTX 970 Mini ITX Graphics Card (4GB GDDR5) which might fit inside the Akitio box. BUT... Power requirement per the spec: 400W (!!!). Is there any possibility of using this card? Would some other card be a smarter choice?