Aluminum Vent repalcement ?

[abl1111]

On my 23' Tsunami there are (2) aluminum, rectangle/boxes for the bow vents. I want to get these replaced and add (2) more to the stern vents ( so if I rub against a pole the cheesey, placstic vents are protected ).

Any idea where I can get them for a fair price. I brought them to a fabricator here and he wanted $45 a pc, un-powdercoated - that's alot just to make (4) bends and a 3.5" weld on aaluminum !