7080 motherboard uses Dell proprietary 6 pin ATX + dual 4 pin cpu, also seen in Dell G5 and XPS 8940, very likely using same pinout following same engineering DNA.

In that case you can probably use Dell 500W psu for G5 etc.  

Y7R0X 0Y7R0X 500W PSU For Dell G5 5090 7070 7060 D500E005P Power supply

Call Dell spare parts to verify whether psu for optiplex 7070 is compatible with 7080.

@redxps630 

"Dell proprietary 6 pin ATX"

It is NOT ATX it is Dell proprietary, 

It has nothing whatsoever to do with ATX.

"engineering DNA" no such thing.  dell computers are not made with genetic engineering.

Optiplex 7080 Spec Sheet 

The 7080 has optional PSU's.  The spec sheet does list compatible GPU's, but not the PSU required for each GPU.

I believe Dell's 500w PSU for the 7080 is enough to power the 150w RTX 2060.  This is according to Nvidia's own website stating 500w is recommended.  The site was uncooperative and I couldn't screengrab it.

But as for the 215w 2070 SUPER, though listed, I'm not confident a 500w PSU is enough, even though it's Dell.  Please see screengrab below.

https://www.dell.com/support/manuals/en-us/optiplex-7080-desktop/optiplex7080_mt_specs/set-up-your-computer

There is an optional 500W power supply for the 7080

@DELL-Chris M   might have more information.

"There is an optional 500W power supply for the 7080"
I also see that data in the guides, but I only see 305W and 255W PSU in the SPMD? I wonder if those charts were mistakenly copied from a different model PC?

Hi @DELL-Chris M ,

I wonder if the SPMD is being a little weird.  In Optiplex's anyway, the 305w PSU was full size (not narrow brick) used in Optiplex's generations ago.  I'm not going to obsess over looking at old tech guides for the 255w PSU, but I do remember it being used in the smaller (older?) models.

And the 7080 isn't quite a full size mini tower.

7080/5080/3080 tower all use TFX thin form factor psu.  
per Chris Y7R0X 500W Chicony = XPS 8940, Optiplex 7080 MT/XE
Typical Dell optiplex line has three tiers, 3080 being entry tier having only one 4 pin cpu socket, 5080 being mid and 7080 being high tier.  5080/7080 both have two 4 pin cpu sockets.  Very likely 360w psu for 5080/7080 is backward compatible with 3080, and 500w psu for 7080 backward compatible with 5080/3080.  It is just Dell did not feel the need to list higher power psu for lower tier line in the same class.

Stock psu for 3080 is 260w, for 5080 is 260 or 360w, for 7080 is 260/360/500w.  It is likely the higher tier line higher power psu is backward compatible with the low tier, as you can see both 5080/7080 entertain budget low power 260w psu which has only one 4 pin cpu connector(they do not require both 4 pin cpu sockets to be connected to power).

7080

Optiplex 3080 Spec Sheet 

Optiplex 5080 Spec Sheet

Yah, those spec sheets probably simply list the way the 3080 and 5080 are sold.

OP original question: What is the part number(s) or the links to where i can buy the upgrade(s)?

Y7R0X 500W Chicony
99TPH 500W Liteon
5K7J8 500W Delta

Dell-Chris M has verified * Y7R0X 500W Chicony = XPS 8940, Optiplex 7080 MT/XE

If OP in US, one vendor link here.