What I use with my Steam Deck and Legion Go (affiliate):

Legion go:
https://amzn.to/3NfKxuh

Steam Deck SD Card:
https://amzn.to/3Yej3Zx

Battery bank:
https://amzn.to/3YZwAE1

My 4k monitor (works great with steam deck, has usbc and power, one cable does everything):
https://amzn.to/3Xl67R9

Usbc dongle to hook up to TV/monitor/external drive/etc:
https://amzn.to/3jJWoFa

Steam Deck Screen protector:
https://amzn.to/3XfHm7Y

Long charging cable (usbc to usbc):
https://amzn.to/3lJyvye

⚡ 45w charging brick:
https://amzn.to/412D470

Controllers I use with steam deck:
https://amzn.to/3RJ2H8y

Internal storage m.2 nvme 2230:
https://amzn.to/3lJ7Txl

Wireless keyboard (also works great with mac, can connect to mac and steam deck at the same time and switches with one button push)
https://amzn.to/3IAAb4U

sit/stand desk:
https://amzn.to/3LqL76s