Personally I would look to see a recovery in Aussie Dollar, Kiwi Dollar and Canadian Dollar if BDI turns upward. I have made this trade several times in the past. I have already started to leg into this by building a position slowly in the AUD. Unless China goes into a death spiral i see this as a core trade for 2015.
Those commodity currencies are highly exposed to risk, though, and you could get a spike down in a flash. As for shipping companies, that's why I mentioned SEA. I'd rather not have direct exposure to any one company who might not be able to weather the downturn.
Not sure why you want to buy a bombed out freight index...in the hopes China will maintain >7% growth rates? Well whatever floats your boat, check out the following equities: (I dug them out from a slightly older source, you would need to check whether they weathered the last 2008 storm):
That is actually quite incorrect. R^2 between BDI and most of my listed shippers is higher than SEA over the past year as well as longer periods (I posted an image, perusing daily closing prices over the past 5 years)