FIT and MTBF would be rather difficult to calculate as you would need to get the FIT and MTBF data for every IC on the board and then calculate from there.
Also note, that the silicon on the Zedboard's that are shipping today are CES silicon and are not production silicon. For higher reliability (read: Lower FIT and MTBF) I would recommend waiting for production silicon.
If you really wanted to calculate FIT and MTBF, you could collect the data for every IC using the BOM - although that would still be a very rough estimate.
