Ok trying this again with full links...
I built a pi TV using an LED display in a display box using this power adapter for input
This allowed me the 12vdc and +2A required for the screen.
FILSHU 5.5 x 2.1 MM DC Power Jack Socket Threaded Female Mount Connector Adapter with 15CM 18AWG Cable https://www.amazon.com/dp/B08272H1SR/ref=cm_sw_r_apa_i_YZF5V42D2VXFT2FXSJ6D_0?_encoding=UTF8&psc=1 - one of these to get the power into the box from the adapter and on to the terminal block below
OONO 16 Amp 2x12 Position Terminal Block Distribution Module for AC DC. https://www.amazon.com/dp/B08TBXQ7H6/ref=cm_sw_r_apa_i_FZ0QJ3VHG2Z27TF7VQAW_0?_encoding=UTF8&psc=1 - I used this terminal block to split up the power between the display and the pi
https://www.amazon.com/dp/B086KTGRH1/ref=cm_sw_r_apa_i_FSN0KBVSTXRVN240DA5N_0?_encoding=UTF8&psc=1 12V to 5V DC USB Type-C Right Angle Step-Down Power Converter, Buck Converter, 15W Output, 3A at 5V USB Type-C Power Supply, Waterproof (12V to 5V USB-C Power Converter) - and this buck convertor to give the 5VDC to the pi.
This "tv" is running LibreElec, and has been working fine in the two years since I built it.
Edit - Photo https://imgur.com/a/CkZ3ESO
Also I guess if the power supply I listed isn't supplying the amperage you need, you could probably go with a big one, but I guess the main point I was trying to get across is that is absolutely doable!