First, wrong forum, you want to probably post in here:
https://bitcointalk.org/index.php?board=67.0Short answer is yes, you can buy InnoSilicon ones directly from them - not aware of any other manufacturers actively selling, and there's a fair bit of them on the secondary market, although it's been getting a bit tighter lately. Prices are a bit high IMO, probably due to BTC's crazy difficulty climb the last month or so...