I've been following this for a while.

You have two main branches to follow

Bare‑metal (native Linux kernel + native drivers) pros:

• True Linux kernel
• Long‑term maintainability
• No Android blobs in userspace
• Cleaner architecture

cons:

• Driver support is the biggest pain point
• • Modems, cameras, GPUs, sensors often require reverse‑engineering
• Power management is worse
• Hardware acceleration may be incomplete
• Fewer devices are viable

You can put this on an old pine phone, or a pixel 3 or a fairephone 4/5 You can buy a preconfigured puresim librem 5 Battery life is pretty rough. You can find lots of youtubes recounting their attempts at daily driving both PostmarketOS, Puresim and UBPorts on bare metal

Halium‑based (Linux userspace on top of Android hardware abstraction)

pros:

• Excellent hardware support (camera, modem, GPU, sensors)
• Better battery life
• Runs on many more devices
• More stable than bare‑metal

cons:

• Controversial in the community
• Relies on Android blobs
• Not “pure Linux”
• Kernel is usually Android‑based, not mainline
• Long‑term maintainability depends on Android vendor support

You can buy preworking models from Volla or you can put it on a Fury Phone there are a number of options for used phones if you want to install it yousel.

IMO, If you want a daily driver with working cameras and good battery life, Halium is usually the practical choice.

You also have to beware of usage in some places, looks like most of the carriers in Australia will refsue to active VoiceOverLTE even though the phones support it.