Hello, the first question is What character, hard choice we do have alot of approvable costume.
you can use this link to find the costume you want
when you find the one it has a list of all the Basic details the armor and softparts have to meet to be approved.
(level 2 and 3 (blue and red) text are optional details but not needed for Basic approval)
databank.501st.com/databank/Costuming:CRLbynamei do have a 3d printed shoretrooper and I can send you links to acquire the STL's.
some are free files but require a little work to make them more accurate, some people have updated them since but take a little to find.
and there is an expensive one but the modeler worked with a large team to make it super accurate like you walked off the set, they even modeled the interior of the armor that was never seen.
here is the link, it does includes Pauls like for accurate armor
and sean fields files which I used for mine that are free but have to look at CRL (costume reference library) and compare to STL before you print just to make sure that detail is present.
shoretrooper.co.uk/also includes the facebook page where you can find remixes of the models or other useful information.
3d printed armor is allowed as long as it doesn't have layer lines present on seen parts of the armor (inside is fine)
although durability is always a question it can hold up really well.
but obviously not as flexible and ridged as ABS vacuumed formed kits or molded casts.
but there are ways to reinforce it with fiberglass etc..
softparts there are a few vendors that are trusted that make custom clothing.
mines from imperial surplus, more expensive but include everything needed, but not most accurate when i got mine)
darkside closet does really nice work (https://www.facebook.com/groups/1742353536003671/user/100064456161791/)
and some more if you want them.
if you need help finding any items i am able to provide more details if that is what you want to build.
or for another character i can help you find kits/stl's/softparts.