You don't need a hd/harddisk, just use AmiPup on a USB stick/pen/dongle
Download and install AmiPup to a 4GB or 8GB USB stick.
AmiPup itself takes some of the space on the USB, but the remaining free space on the USB can be used just like a hd/harddisk,
that you can install linux/amiga programs on, or create/save documents or files on.
So no need for a real harddisk in the laptop, just use the USB as a harddisk
When AmiPup boots it copies systemfiles from the USB to the RAM on the laptop, so something like 4GB RAM on the laptop itself is good.
This makes AmiPUP *REALLY* fast to use (the boot is a little slow because it copies files to the RAM) when finished booting.
All your linux programs will open in milliseconds, because everything runs from the RAM on the laptop and from the USB stick, not from a slow hd/harddisk in the laptop.
I used AmiPUP exactly that way (installed to a USB and copied to the RAM) for a loooong time and it was the fastest system I ever had, and I installed lots of linux programs on the free space on the USB