" I have not yet personally seen anything that uses it (fire wire b) but it is backwards compatible "
If it is not loudly written all over your card it is probably ( the more than sufficient) firewire a...........

Unless you use older kit ( which it seems you clearly do not) you are more than likely to get great acceptable results [/quote]

Your need for speed does not require you to have firewire b. It is available but not mainstream enough for you to feel you are missing out WHATEVER your current need
If you are really must get on an (extra) internal hd you could step backwards and buy an extra ide pci interface card ( not really recommended) f)