I would go through the wholesale house. I don't think it should be a matter of money so much as a matter of quality. For the same price or a little more you can get alot better product. Theres a reason that its so cheap at Lowes.
1. i am installing a supply vent directly above a window (i read thats where your supposed to do it... and the contractors that quoted me a job said its supposed to go there too). BUT, how far out from the wall should I come... whats code? looks like 6 inches to a foot is fine.
2. i have 6" takeoff that i need to cut into the supply line. i thinks its a 7"(oblonged looking) hole then goes to 6" pipe .. its adjustable. My bro-inlaw gave me his elctric shears to cut with.. cutting not problem.... just that want to know, do i cut a circle hole or the oblonged looking shape of takeoff? whats the standard practice to get a take off started? TRACE A 6" CIRCLE? sholuld slightly smaller right?