There should be no less than 4 or more network card interfaces.
The general requirements for the processor are not very great.
Memory 1G is enough.
It is best to use solid state hard disk or DOM commonly known as electronic disk for system storage.
The interface of the network card is preferably gigabit.
As for soft routing, if you intend to operate for a long time, it is recommended to use genuine soft routing. If the estimated time is not long, then use the cracked version.
There are also soft routes that are basically used at present, such as Sea Spider and Vorgias, which better support multi-WAN.
There is also X-wall soft routing, which supports traffic shaping PA, which is also quite good, but it is still quite good for a single WAN, free of charge.