Use *Two* Thunderbolt/Firewire adapters on MacBook for 400 and 800 devices?
Each Firewire controller will be treated independently by OS X, and each controller will have its bandwidth set by the slowest device connected. So you could daisychain your devices but will only see 400Mb/s throughput, requiring you to use separate Firewire adapters if you wish to see your OWC drive running at full speed.