Are you planning on ordering the mannequins through a service? Because I know Shapeways prepares the prints for you. all you have to do is submit the model.

I forgot to mention I am not going to use Shapeways. XP

is shapeways a bad service?

Dunno. Never used them. I would actually rather commission one of my fellow artist here in this community.

Try checking with ? They did a little 3D print for recently.

I have also seen and do 3D prints.

Just a few suggestions...have you tried searching for something similar to what you're looking for on https://www.shapeways.com/ or a similar site?
Or the figma archetype series - they make a clear one. https://www.ebay.com/i/142210768340?chn=ps

Most important thing to keep in mind when getting a sculpt for printing is HOLLOW THAT FUCKER OUT. Printing a hollowed sculpt will cost a LOT less than a solid one. Keep in mind you're going to want a 3mm wall thickness for most printing materials.

Now THAT is a great tip! Thank you!

1/3 size? So about 2 feet? You do not want to use SLA for that, you'll be spending hundreds of dollars on resin if you do. SLA is good for parts with high detail, and maybe a max of 6 inches in the largest dimension (from a practical perspective. You can go as big as you like by printing multiple pieces, but like I said, the costs will be absurd).

FDM would work well for that kind of application. Expect a few days print time unless you want to augment your machine with a high flow print head (sacrificing surface finish and detail), up to a week or more if you want to get higher detail. Material costs should be relatively low though.

As far as the modelling goes, you'll want to make sure that your model has good topology so as to not give the slicing program fits trying to figure out where the surface actually is. You'll also want to make sure that the model is airtight rather than being composed of overlapping surfaces. Other than that, keep in mind that any overhanging surfaces will suffer from poor print quality and/or require support material and sculpt accordingly. Usually it pays to plan ahead to split the model into multiple pieces so that you can orient them for easier printing (and save the heartache of having a multi-day print fail part way through and having to start over from scratch).

1/3 scale but no legs. Just the torso! Soooo about 14-16 inches tall (with head)
That's what I was thinking too. Just a simple FDM print for the torso because since it is already so large, there isn't any extremely fine details to worry about.
That is an excellent idea breaking down the parts to prevent hours of wasted time. I am taking all the notes I can get with this. Thank you so much! You've actually
helped me narrow down what I should really get. I DO want the SLA and just outsource the bigger less complex pieces for the FDM. Now to find someone who has
an FDM printer...

hnnnnnnnnnnnnnng

You need some one to print and ship it to you?

Yup!

I will see what I can find out.