A standard BIMARE 18HT section should be fairly good for the N20 (it is considered too stiff by a large majority of 18HT owners).
It scales up at just under 16 Kg or 35 lbs (its "heavy" weight is due to its "low" profile - 145 x 59 mm).
In Europe the complete mast retails at 3,300 EUR (USD 4,290)