You want cheap ? Cheap is my middle name.
They're probably too light weight for a 11' rod, but I like to use spinning rod reel seats...they're around 5 bucks for a good one and very light weight (which might not be what you're looking for). Then you'll need to add a butt cap, fighting butt, or simple glue a dime on the end..
Many official fly reel seats can be installed up or down, but you will need to add a butt cap..... they're like 50 cents tops
often has some good deals on rod building supplies....
such as Pac-Bay reel seats half price