I'm thinking about going with pad hacks after two PMs to Vigo with no response.
Sorry man, I have just been working on changing around my offerings and calculating out costs and didn't want to give you any bad information. I should have given you a heads up on that, sorry. I will just try to cover your questions here, I hope that works for you.
Regarding your xbox adaptors, I don't own an xbox to test any adaptors myself, and I haven't received an confirmation from any buyers on whether or not they were able to get it to work on their xbox. Sorry, I'm not much help there.
With the PS2 cable, I am planning changing my bundling offerings so that the encoder will come with only a PS2 cable or the USB cable. Since the PS2 cable will be able to still work with PC and PS3, I will not be bundling both cables any longer. I still haven't figured out pricing though. I haven't been making money bundling both cables, I haven't finished figuring out what price point I need to be at yet.
I do sometimes offer volume discounts in the form of my passing the shipping savings to the customer for putting more than one item in a package. It really depend on what how much I ship as to if I can offer much savings, and I just handle that by doing individual price quotes.
You could potentially make your own PS2 cable for these boards as well. I believe the pinout on the board is a linear match with the PS2 port, but I haven't personally tested yet. The trick issue with making your own is that you still need the USB port as well. This is critical because it is what powers the encoder. The cables I sell have both the USB and PS2 port in the same cable, but I believe that you could just use the standard ZD ReMatch USB cable and wire in your homemade cable in the port. I think it would work fine as long as both ports are plugged in at the same time.