cheap and low power python device

[DeaD_EyE]

and device requirements:
1. can run the above package,
2. can download files with sizes above than 4GB
3. have store 100+ GB of data(probably using an SD card or USB stick)

any clue what device I must use?

An Intel Pentium I with 100 MHz could do this task with Python 3. If the machine does not have enough memory, you even could use Micropython. To be realistic, 128 MiB RAM should be available.

You could use a RPi0 W or a RPi0 W2 with an attached USB-SSD/HDD to do this task.

The maximum file size is defined by the file system which is used.
Use ext4 or something else. Avoid the use of FAT. The Fat file system single file site limit is 4 GiB.