Yeah man, check out the accessories part of the forum...
http://forum.ppcgeeks.com/htc-evo-3d-accessories/
I ordered one from Amazon to have right away while I look at/wait for more "advanced" protection if I am not happy with what I get. I'd like a case that adds a kickstand myself (I want to see what the Seido one looks like to compare to the one on HTCpedia).
If you were interested at all, here's the one I ordered from Amazon:
Amazon.com: Amzer AMZ91139 Soft Gel TPU Gloss Skin Case for HTC EVO 3D - Black - 1 Pack - Case - Frustration-Free Packaging: Cell Phones & Accessories
I also ordered a screen protector for it too. You should be able to find that stuff. And as another poster said he's done, I've ordered myself spare batteries that are on sale on ebay (they ship from Hong Kong (HK)). I ordered 3 batteries plus a quick charger for about $17 shipped (free standard shipping from HK).
I like the idea of having something for it as soon as I get the phone too, then taking the time to consider/look at the other available cases or screen protectors I may or may not like better.
Good luck!