Using IPSEC in local network only ?

Alloha people,

I have now a local FreeBSD NFS-server, but in my house is almost everything wireless, so i wanna secure the client-connections to the NFS server with IPSEC.
(my wireless network is also secured)

Is this a good solution? And is the speed fast enough, so i can watch movies on the clients, that are physical on the NFS server?