Salutations.
They are made of leather. As to what kind, I am not certain. If you are interested, here is the webpage for the boots that I purchased.
http://www.scaboots.com/Mens-Sir-Henry- ... T_p_1.html

Salutations. Here is also another person that I can think of that does saber pikes http://chaucer44.squarespace.com/
But, this person is in the US, and I am not certain if they do international shipping.

Salutations. Went looking on Esty and found a helmet here is the link: https://www.etsy.com/listing/594316464/coruscant-guard-helmet?gpla=1&gao=1&&utm_source=bing&utm_medium=cpc&utm_campaign=shopping_us_a-accessories-costume_accessories-costume_hats_and_headpieces&utm_custom1=f0e00159-8b28-4536-a431 ...

I do apologize for the WTF mention. Should have paid a little closer attention.
Found this one on Etsy. It looks like it has a narrower shoulder section, but the size is not mentioned. https://www.etsy.com/listing/272716232/star-wars-imperial-guard-shadow-guard?ga_order=most_relevant&ga_search_type ...

Salutations.
The only other vendors that I can think that offer Shadow guard helmets, those are Kamino Customs and Walt's Trooper Factory. Are you wanting a finished helmet? Because I believe both vendor's helmets are an unfinished product.

Hope this can help.

That's true, I knew that they are not shown in the 501st CRL, as of the last time I checked. I was just wondering was an unofficial change that had happened that was just making its way around.

Salutations. Just received a post on facebook from the Sovereign Protectors. In several of the photos, there is a Shadow Guard carrying a what looks like DH-17 Blaster.
https://www.facebook.com/501stSovereignProtectorsDetachment/photos/pcb.2853522158010618/2853521758010658/?type=3&theater
In the ...

Hello Again. Here are some pictures as what I have been working on as of late.
This is my gloves, pouches, and belt with buckle
http://www.sovereignprotectorsarchives.com/images/2019/09/04/Kir-Kanos-Build-1.jpg
Here is the undersuit.
http://www.sovereignprotectorsarchives.com/images/2019/09/04 ...

Salutations. You could PM Lucious Talvloinne about this. He was one of the first people to make the Carnor Jax costume for the 501st.

Hello again.
Have you tried this seller? http://goldenarmor.com/force-pyke/2011/ ... Position=0. I think it costs about $135 plus shipping.
Good luck on the build