https://airandspace.si.edu/collection-objects/pressure-suit-apollo-a7-l-shepard-training/nasm_A19750836000http://www.astronautix.com/a/a7l.htmlAccording to this, the training suits were just the suits, though a different one than the flown article. Which makes sense. Why go to the effort of creating something that replicates the the look and feel of the suit, when you can just have the suit? Cooling would be a little different, as sublimation cooling doesn't work so well in an atmosphere of any thickness, but the liquid cooling garment itself would work just fine as long as the water could be cooled. In fact, fursuiters and cosplayers with big bulky costumes sometimes use the same idea with ice water pumped through tubing sewn into a vest or shirt to provide cooling while walking the floor of the convention and similarTo sum up a somewhat rambling post, almost any source for the flown A7L will be of use here as well.
This isn't bad for some early designs...https://web.mit.edu/16.00/www/aec/spacesuit.htmlBut this is a pretty good ebook:https://www.nasa.gov/wp-content/uploads/2015/04/dressing-for-altitude-ebook_tagged.pdf