help with tricky gpu upgrade

[J400]

2 years ago my friend purchased one of these:

https://www.amazon.com/ASUS-G20AJ-US023S-Desktop-Discontinued-Manufacturer/dp/B00OFQR0XA

 

it has an i5-4460 and a gtx 750. recently he purchased a 1440p display and some new games. as expected, a 750 (non ti) doesn't handle 1440p well. especially battlefield 1. so he's looking for an upgrade. only problem is, this system runs off of an external power brick, and gpu power is drawn straight from the pci-e, which means there probably aren't any 6 or 8 pin connectors for the gpu. so i made this post for those who might have experience for these things. I haven't tried taking it apart to see for myself yet either. but i believe it can fit a full size reference nvidia card. like to see if anyone has any ideas.

[Mohenjo]

maybe a gtx 1050ti would be good? not really a 1440p card but it has the same power draw as the 750 ti but is way more powerfull 

[Megah3rtz]

gtx 1050TI only needs 75w of power and is external power connector free. 

[Megah3rtz]

if you'd like a 1440p graphics card, you'd have a really hard time finding one without a 4-6pin connector. 

[SmashinMachine]

I found this here.

 

[gustal]

I currently have the g20aj i7 4790 and a gtx 1070. Works great without a single problem.