XPS 8300, upgrade FYI

Here's my experience with upgrading the XPS 8300 with a new PSU and GPU 
Stuff Wanted: GTX 1660 and a 650-750watt PSU

O.G. PSU Stuff
Dimensions: 150mm (W) x 86mm (H) x 140mm (L)
DELL PSU 460W:     Minor Rail - 3.3V (17A) : 5V (25A) Combined = 142W

Here's the closest I could get on my budget (same dimensions, minus 12W from original 3.3/5 combined)
TX750M PSU 750W: Minor Rail - 3.3V (25A) : 5V (25A) Combined = 130W 

Since I read about the Wifi of this XPS 8300 not being compatible with Windows 10, I removed that wifi adapter/card years ago. Also, the new Windows 1809 update disabled the built-in NIC. I'm hoping this will lessen the need of the full combined 142w? I'm also hoping dell made these OEM PSUs with headroom.

Anycase... the GTX 1660 is not compatible with XPS 8300 (i7 2600) :Crying::SuperAngry::Embarrassed: I'm thinking it's bios related. I don't see Dell updating this bios anytime in the future... OEM stuff... I tried, failed, then found a post with someone going through the same issue I had, confirming it.

https://forums.geforce.com/default/topic/1104949/1660-ti-incompatible-with-my-sandy-bridge-i7-2600-system-/?offset=3

Note: I was able to get the 1060 to work (and that worked with the OEM Dell PSU, but I'd still get a better one).

What are your thoughts?

Do you think the removed Wifi and disabled NIC will help with the lack of 12 watts (from combined 3.3/5)?
The last thing I can think of is getting a new case or mickey-mousing this one to fit longer PSU

I'd rather wait till I'm ready to continue building my custom to do that. What do you think?

Here's what I'd get if I can only make it fit. 20mm too long :( 

RM750X
Dimensions: 150mm (W) x 86mm (H) x 160mm (L)
https://www.corsair.com/corsairmedia/sys_master/productcontent/RMx_2018_Manual.pdf

I also found a hidden spot for an extra fan. Photos included.

OEM PSU SpecsTX750M Specs

PSU spot with ruler

TX750M Placed

Hidden spot for extra fan

Extra fan place @ front bottom.