I am with Eddie on this one I say go for it!!
If I wasn't such a TIGHT WAD I would break down and buy one myself. I have been using my Singer 15 treadle for all of my quilts and most of them are queen to king size. Let me tell you its an adventure to say the least but I enjoy the challenge!!
Since I am really good a fabrication I have been toying around with building one and using a Singer industrial like a 29 or a 31-15 for the long arm. I have a buddy that owns a machine shop and I can use it anytime I need it, so I am thinking for around a grand I could build me a really nice one.
Billy