Just from the hardware side. I'd have to check the data sheet again but I think the AI on that device is multiplexed. This usually means you will need to take the aggregate sample rate in the manual and divide by the number of channels to get your sample rate per channel. I think the ADC is 500kS/S so you won't be able to read 6 channels at 250KS/S.
Check the manual to be certain.
As far as processor and bandwidth it will depend on how you write your embedded code (what scaling/cal, etc is your process doing) and how your wireless network is set-up. Wireless generally is more bandwidth challenged so you may have trouble streaming that much data. You might consider doing some data reduction on the device instead of trying to stream everything. You've got a CPU and FPGA, might as well use it.
