Hi,
What is the end goal you want to achieve - have separate wood plank textures and use with Floor generator or a flooring texture?
It's mainly same type of work, but can vary depending on how you plan to use the textures to be created.
I think your best bet will be to use Substance Designer, it's a very well known and used software for material creation, especially procedural. It should have some ready made assets and library where you can start from.
Other than that, yes, it's a manual work, and it should be done manually if you want the ultimate quality - taking good photos of wood textures (floors, planks, veneers) and then generating a materials from it, and then baking out the maps.
From my practice, any wood material can be created using the sources available online. There are endless patterns available and they can be used to generate new ones, even with simply mixing them together.
I would also try to convince the client, if that is the case, that the pattern seen in one image is not the definitive look for the final wood material (if it's just a plank) - the same pattern will never be repeated and the overall look-and-feel needs to be achieved.