Thanks. I went to the lumber store and they only have 12 foot lengths of the plastic material. That would cost me $40. And i would have 10.5 feet left over.
So. I bought some 1.25 " square aluminum and made a frame for outside. Tig welded it and its ready to roll.
The aluminum frame will actually make it very easy to install. I can screw the vent to the top of the frame. Then i can screw the whole assembly from the inside to the bottom of the frame and sandwich the boler in between.
As for the knob with my foreheads name on it. I have plans for that baby.

I cant exchange the fan for the low profile because i ordered the fan from the US(Thanks Donna D) solely because Canada wanted to RAPE me of my money. I could pay $400 and get it here or pay $169 and get it there. Hmmmm. Which one to choose.
This fan should work out fine now.