Last year I was pleased with the way my Icurass/Extra styled 3mm depron flew, for this season's indoor series I have copied it.
This is just a cut down Ikurass Extra with an increase in the rear fuselage and side area. It flies a little slower than the Extra and is a lot easier to prop hang and knife edge, it was optimized for the small hall at Churchdown but flew fine in larger space at Bentham.
The side area is large and well forward, this allows it to slow  roll with very little rudder and elevator input

Motor Dualsky Nano! XM2812CA 19gram 80W brushless 1200 revs per volt
10 amp speed controller
4 Esky 9gr servos
All up weight 5.5 oz
Prop 8 X 4 GWS
Battery 500ma 2 cells

Battery on top

reinforced with carbon tows.
Push rods and wing braces are 1 mm carbon, undercarriage legs are 2mm tube. Undercarriage fixing points are reinforced with fibreglass sheet 

The yellow plan form is one piece, paint it before assembly . 

horns are fibre glass, 0.5mm ply is OK, hinges are taped one side and siliconed

the front, motor is screwed to a carbon tube, there is no side thrust, the large vertical fuselage cancels out the rudder side force

The model is meant for indoors and is only happy outside when it is calm. The C of G is on the centre spar and gives the model a tail heavy feel, this stops the nose from dropping in a stall, there is no pitch stability.
Only a small amount of top rudder is needed for knife edge, this can be adjusted by cutting away the vertical fuselage in front of the C of G