I wonder if Polarflo have a DDC (they market as the TT Series 350) replacement housing in the works considering they have made one for the D4 (marketed by them as the TT). Its a bit 'bling' and certainly expensive for no performance benefit, but they might be able to help you out making something that will accept metal barbs.
Remember for $75 you are paying for a higher quality industrial component - it was designed to work without breaking or maintainance for a very long time - pretty wasn't one of their design criteria. The C-Systems pumps looked great externally until they proved too good to be true - seeing how some of them fell apart internally
