I dunno if the volume is right, that depends on the subs.... sounds prolly close, around 1.75 cubes for each sub.
But that port... how big is it in area and volume?
ive used just over a gallon of resin and 2 packs of glass mat. i used one pack of glass cloth. its ALOT easier to go around curves and bends. does it matter what is used as far as fiberglass goes. the mat just gets everywhere.If its to thin it will sound "pingy".You want it to be as solid as possible.A box that size I would use probably 2-2 1/2 gal. resin and probably 3 or 4 packs of glass mat.