Process particular file type from mixed files to jpg

Hi,

I am a photographer and have a huge bank of images, usually filed in external hard disks, containing client folders with sub folders of .psd, .tiff, raw or jpgs.

I am looking at an action / conditional action or a script to apply to only folders or files with .psd or .tiff files and to save in the same folder order.

For example, when I run a script to a Hard disk or a Main folder, I can save as Jpegs and keep the same folder structure.

But this only works on all the files.

I would like to run an action / conditional action or script to an entire hard disk, and have jpgs created of only the .psd, .psb. or .tiff or on images of size more than 5mb, but yet keep the same folder structure.

I am trying to create a bank of my finished files in Hi res quality JPG so I can upload to the cloud so as to have a permanent backup.

I have 50 1TB hard disks and it is not possible to go thru each and take out only particular file formats.

Any help or a script will be appreciated.