8bitdo wireless bluetooth adapter > usb > arduino > saturn controller port

I want to use a wireless controller with my Sega Saturn. Unfortunately they all suck
I'm envisioning a little project box with a saturn controller cable plugged into the saturn on one end, an arduino inside, and a USB port with a 8bitdo bluetooth adapter plugged into the other side.

The problem is I really don't know where to get started with this project!

I don't have much knowledge of the arduino, is there a better product for this role? Keep in mind low latency is VITAL to this project.

I basically need to decode the data coming from the bluetooth adapter, reencode it for the saturn, and output it through the controller cable.

It doesn't seem especially difficult to wire it, but I don't know where to get the decode / encode information.

Advice appreciated, thanks!