Yes that's all I need and sounds much easierIf you simply want your NAS to stick to the same IP you may even be able to just set it as such on your router, basically fix what ever DHCP address it was given so it never gets released and reallocated to something else.
Mac Binding (or bind IP to MAC)
You are right I didn't know lolI know that. OP probably doesn't.
That would be greatI'm sure if you let us know which router you have we can steer you in the right direction.