Yeah, I've never seen a Cool Boy cart with any 16-bit games on it - IIRC some of the packaging and manuals advertised dual 8/16-bit compatibility, but I have no idea if that was true, or if they were just referring to VT03 as "16-bit" as companies sometimes do.
if you want one, DX has them:
http://www.dealextreme.com/p/cool-boy-2-4-color-lcd-portable-game-console-with-tv-out-12127?item=4But they can be had way, way cheaper on Taobao, just search for 小霸王 (Subor) Z07, Z08, Z09, Z10 or Z16 (Z12 is the model that plays actual famicom carts) There's also TC8281 and TC8288 - the 2-player versions - which I think are still made by Subor, but they don't put their name on them, so you'll just have to search for the model number in those cases..
You can also find carts and accessories with the same search terms. Beware of misleading listings for generic items like PVP Stations with "Subor Z(whatever)" in the title though, there are a few on there.