Yep... I echo a lot of opinions here. You only spent $60 for that setup. The best thing you could do is put it on ebay. You'll get $150 or more for it. I'm sure it may be a bit more actually... as long as the cd attachment works well.
Make sure you test it with a game that doesn't need the system card (or do they all need one???? You may just want to sell as is... being that you got the goofy game to work.
Then... simply get a DUO. You can get an American one if you want... but I think your cheapest and best option is to buy the PCE Duo-R. Get it modded... and then you are set.
http://www.pcenginefx.com/forums/index.php?topic=3531.0
There's one for $170 shipped. Great deal and great job on his mods.
My investment from him was one of the best I have ever made.