You use both of my favorite clearos: the Innokin i30S and the Aspire Nautilus, although I use the 5ml version of the Nautilus. Do you use the BVC heads with your Nautili? Most people, including some in this thread, find the BVC heads to be significantly better than the BDC heads.
I hope you find the iStick 50 soon, because if you don't, I know for a fact that denizens of this thread are more than capable of pumping up some fascinating alternatives. But, even I can find the iStick 50 at places that have them in stock.
Use coupon code VC10 to get another 10% off here, bringing the price down to $45.
iSmoka Eleaf iStick 50 Watt Full Kit
Don't worry, we'll find one for ya! Take two, they're small. (I have no personal experience with the iStick 50.)