I can't answer question 1 but it sounds like for 250 tunnels you would want to use more then one device to handle the load.
I would look for a solution that offers seamless load balancing.
Question 2. is yes it has a gui but for what your doing there is going to be some command line involved.
I would look for a solution that offers seamless load balancing.
Question 2. is yes it has a gui but for what your doing there is going to be some command line involved.