XFX and MSI and possibly others, arguably big-name brands, have relased factory overclocked 8800GT cards - I have one from MSI and it works fine. At least it seems to. So OC’ing these chips isn’t impossible out of hand. I agree with AndreiB, you can always clock it down. Besides: A card that’s built for OC-ing and then clocked down to normal frequencies should be at least as stable as a normal card. I guess.
The unknown vendor is a bit of a question though. I’d go for one for gaming, but … hmm … for CUDA.
Also, there was someone with an 1GB card here, and it was a bit slower IIRC. There’s a forum post about it.
The 8800 GTS (G92) seems to have quite a bit of headroom for overclocking, even when air cooled. I was amazed to find a guy in Quebec who has a small business buying 8800 GTS (G92) cards, modifying the voltage regulators on the board to allow the various internal clocks to be massively increased, and then selling them as custom overclocked boards on eBay.
That said, it is concerning that the manufacturer has a clear typo in their product specs (112 instead of the correct 128 stream processors) and an ugly banner ad for business cards and domain registration at the bottom of the page. I would be hesitant to buy this card unless I really, really needed 1 GB of memory and the G92 features (PCI-e 2.0, atomic global ops) at the same time. The 8800 GTX is almost the same price, and gets you 768 MB with more memory bandwidth, and the 8800 GTS (G92) 512 MB can be purchased from better known manufacturers for almost $100 less.