You could purchase the Lian Li USB 3.1 Type-C Gen2/10G IO Port Cable PW-IC01NH45, make an appropriate cutout (say, through a blank 3.5" case insert panel), and install/attach it it that way. The latest packages even come with compatible mounting screws (to fit the cable "head").
If you want an already made-up front panel with USB 3.1 , Lian Li makes one, but it is made as a replacement for some of their existing cases/front-panels. You would either have to have one of the specific Lian Li cases, or be willing to cut and/or modify an existing case to try to fit the Lian Li USB 3.1 front-panel
in it.