Hi Dave,
Welcome to our forum and thank you for your interest. We got a few requests to make a module for the BDP-105 as well, but I am sorry to say that we don't plan to make one due to economical inefficiency of doing so. The BDP-103 and BDP-105 are identical in terms of audio and video playback capabilities (the same applies to D versions). The "only" difference is USB input and analogue audio board (expensive DACs). You pay 35-40% more for BDP-105 just because of higher quality analogue audio board that you would throw away if you were to replace it with a digital output board like the Vanity. Unless you really need USB input (which can be replaced with an external USB interface), it would make much more sense to sell your BDP-105 (if you already have one) and get BDP-103 with the Vanity103 board. Unfortunately the Vanity103 boards wont fit physically into BDP-105 without crude mechanical modification of the back panel and internal cabling.
Regards,
Pavel