The nose will add side area. Remember that any fuselage side area in front of the wing requires nearly 3 times the area (or distance) behind to counter it. It not just the rudder but the combination of the fixed fin and rudder than matters. Keep the nose as short as possible yet consistent to obtaining the correct balance point.
Is it just a glider or will it have a motor on the front?
For adequate stability and control with that big wing both the tail plane and elevator need to be considerably larger, at least twice the size.
Too much tail area might reduce the glide performance just a bit but too little area and it will be hard, or even impossible, to control.
Proportions something like this home built electric powered glider?