Linear Bar (Slot) Diffusers for HVAC

I've searched and searched and can't seem to find anything...I'm trying to get a rough idea of what linear bar diffusers will cost (style like this link):

http://www.metalaire.com/products.as...600&family=LSD

I've got my local HVAC supplier working up a quote for me, but I'm don't want to just trust that his price will be reasonable. Can someone give me a rough idea?

Oh, btw, I'm planning for 450 cfms and <250 fpm face velocity. And I understand that these things require substantial plenums...that isn't too big a deal for me. I just want to make sure I don't get ripped off.

I'd probably want to have them no more than 10' wide total since my room is going to be something like 10' 9" once the GOM frames are on the walls.

Thanks Dennis...I'll have to check with Ted on Monday...didn't realize they could get these. I was actually mentally prepared to only be able to get them in white and I was planning to use the Core's sandblasting and powdercoating equipment to make em black, but if Ted can get them in black....