I suggest

Tesaurox,
Tesaubox,
Tesaunox.

They are all mixtures of the Greek 'Thesauros'=treasure house, the Spanish 'Tesoro'=treasure coming from the same source, and the English word 'Box'. The last one I created because it has a similar sound like 'Knox' from 'Fort Knox' for all those which are more familiar with modern than ancient history.

Have fun when picking your name!
Edit: Please also feel free to use it as a starting point for further modification, I am not interested in the bounty. This should be fun!