Very often you can find informations deeply buried on the manufacturer website, or send an email to the technical services to get a list of different chip used for a same model, and the matching serial numbers. But since manufacturers always write in their licenses agreements that they reserve the right to change product "specification" you cannot hope for much from their side.
You best bet is to check the return/exchange policy of the vendor, if you are going to a store ask directly the vendor about the nature of the chipset, he won't be able to answer most probably so to make the sale he will guarantee you can return the product if not the one expected.
Aside from this I have two Netgear wlan atheros-based products and never had to struggle to find the one I wanted. Netgear isn't really on the cheap side, so maybe more interested in maintaining their reputation of quality than cutting corners... but it's impossible to guarantee what's in the box without trying it.