Lou,
I am just starting to put together plans for a forge myself. I have seen pics of an "in-line" fan with what appeared to be 190CFM VEN-Tech 4" used on a bottom air Forge. I was able to find what appeared to be that unit on Amazon for about $70. A little searching and I was able to find another brand with mounting bracket and speed controller for about $60. They are typically used for horticulture or ducting and appear to be suitable for static pressure use.
Dave with Fiery Furnace Forge was the one making the forges, saw the fan on his facebook page. I don't know if he's still selling that unit or not, but he responds very quickly to facebook messages.
