Topic: Expanding number of analog I/Os by adding more FF800 units?

Hello Everybody,

I am using Win7/64+Cubase7 and two RME FF800 (daisy chained) units (via FW800).
It works fine but I need more analog I/Os (mostly Inputs) for my setup.
What is the best option to expand number of analog Inputs and be able to record all analog channels separately in Cubase?
If the option is to add more FF800 unit, how many of them can I chain? 
In PC, my FW controller card has two FW800 connections. Should I connect FF800 units into one chain (to one FW port) or should I use both FW ports? Or maybe it does not matter? :-)

Thanks for any help and suggestions.
Greetings
Tall