I'd honestly just order what you need from bricklink. Alternatively get used Lego by weight from ebay. Around here you get a kilogram of unsorted, good quality Lego for €20.
1: https://www.bricklink.com/catalogList.asp?catType=P&catID=22
2: https://www.bricklink.com/v2/catalog/catalogitem.page?P=3937...
3: https://www.bricklink.com/v2/catalog/catalogitem.page?P=3036...
4: https://www.bricklink.com/v2/catalog/catalogitem.page?P=3038...
Or try the local Goodwill Auction site (if you drive to pickup you save on shipping and can outbid others).
Two flat pieces back to back are very very close to the width between the sides of two rows of bricks separated by one row of empty studs.
Here is a photo [1]. Here it is with the three top braces and the cable holder removed so you can see everything [2].
This the LEGO compatible case I'm using for the camera [3].
[1] https://imgur.com/a/ggNe5uM
I bought a case for the Raspberry Pi camera that has a LEGO-compatible back and a small LEGO set (10692) specifically for making things to hold the camera where I want it. It has worked great.
Question for LEGO geeks: my set only has one L-bracket, and it is quite small. Looking at other sets at local stores, they also only have one or two small L-brackets.
Is there some way other than L-brackets that people use when they want some LEGO assembly to connect perpendicularly to some other assembly?
Or should I just order an assortment of brackets from a third-party LEGO brick marketplace site, like this [1].
[1] https://www.bricklink.com/catalogList.asp?catType=P&catStrin...