Could you clarify a little on what you mean by "QWERTY/Chinese keycaps"? My understanding (which may be incorrect) is that mainland China mostly uses an ANSI-US layout with extra legends. I am not sure about the other Chinese-speaking regions. If that's what you want, the
Pimp My Keyboard "Chinese Alpha set" on this page is a good option (if you like DSA profile). You could add in their ISO modifier kit to get access to the ISO Enter and the smaller shift key.
If you are looking for something like, say, a UK layout (" on 2, £ on 3, etc.), but with Chinese sublegends, I think this will be difficult to find. You could mix and match with the ISO base kit and the 60% alpha kit on the above page, but you'd lose Chinese sublegends on the numbers. Depending on *which* sublegends you're interested in this may or may not be a problem -- Cangjie only uses the QWERTY keys so you'd be fine, but Zhuyin and Dayi both make use of the number row.
If you're looking for Chinese monolegends, without the standard letters, numbers, and symbols, there are a couple of GBs coming up to fill that need:
GMK Houhai (and a WoB Cangjie alternative that will hopefully be announced soon) and
SA Outlander for Cangjie input, and
KAT Monochrome for Zhuyin. I am not aware of anybody producing a Dayi layout set at present.
Hope that helps! If you're looking for a particular ISO layout, please post the layout here, as just "ISO" is a little bit too broad a category to be able to offer you much advice. Also, it would be useful to know which Chinese legends you're looking for, if you have a preference.
