uCOS-II foot print and port interrupt latency

Hi everyone,

I am new here. I am planning to buy a set of Nios II Development Kit (Stratix II Edition) for a stringent memory requirement project development. Can anyone shed some lights on the uCOS-II (any other small foot-print RTOS available?) foor print size and interrupt/task swtich latency of the port? Also the TCP/IP stack size and performance on top of the uCOS?

Thanks in advance.

- icrona