mac mini i7 2012

Been looking around for a 2012 mac mini but I have questions about being able to integrate/attach several older drives to the new mini.

Currently using an older, 2006, mac pro desktop with four internal drives of various ages and sizes plus one external drive, also old. I would like to be able to copy these into a smaller configuration onto newer drive(s). Most of my graphic/video editing software is old; photoshop cs3, after effects cs4, final cut studio 2, as well and will only operate with snow leopard.

One question is, will it be possible to link these older OS/software programs to the mini with the operating OS of high sierra? One of my drives was operating with lion and able to upgrade to sierra but this was done on another, newer, mac pro which is now dead due to salt air and a hurricane. :{

Also, are there any recommendations as to where to look for such a device other than the very expensive refurbished department within apple?

Thanks for your input.