I know that an item mod it's not a big deal to translate, but hey, it's not a big deal to translate!
Here's the spanish translation to the current items. It should be in a new file called XComGame.esn on \Localization\Translations with this content:

[Hat_Capnbubs_Beret_M X2BodyPartTemplate]
DisplayName="Boina de campo"

[Hat_Capnbubs_Beret_F X2BodyPartTemplate]
DisplayName="Boina de campo"

[Hat_Capnbubs_BeretBadge_M X2BodyPartTemplate]
DisplayName="Boina de vestir"

[Hat_Capnbubs_BeretBadge_F X2BodyPartTemplate]
DisplayName="Boina de vestir"

[Hat_Capnbubs_HeadsetBallcap_M X2BodyPartTemplate]
DisplayName="Auriculares y gorra"

[Hat_Capnbubs_HeadsetBallcapReverse_M X2BodyPartTemplate]
DisplayName="Auriculares y gorra hacia atrás"

[Hat_Capnbubs_HeadsetBallcap_F X2BodyPartTemplate]
DisplayName="Auriculares y gorra"

[Hat_Capnbubs_HeadsetBallcapReverse_F X2BodyPartTemplate]
DisplayName="Auriculares y gorra hacia atrás"

[Capnbubs_BalGoggles_M X2BodyPartTemplate]
DisplayName="Anteojos balísticos"

[Capnbubs_BalGoggles_F X2BodyPartTemplate]
DisplayName="Anteojos balísticos"

[Capnbubs_BalGogglesClear_M X2BodyPartTemplate]
DisplayName="Anteojos balísticos limpios"

[Capnbubs_BalGogglesClear_F X2BodyPartTemplate]
DisplayName="Anteojos balísticos limpios"

[Hat_Capnbubs_BalGoggles_M X2BodyPartTemplate]
DisplayName="Anteojos balísticos"

[Hat_Capnbubs_BalGoggles_F X2BodyPartTemplate]
DisplayName="Anteojos balísticos"

[Capnbubs_TechMask_M X2BodyPartTemplate]
DisplayName="Máscara táctica"

[Capnbubs_TechMask_F X2BodyPartTemplate]
DisplayName="Máscara táctica"

I hope it helps :)