Stick to your guns on the king sized frame... Last spring I purchased a Hinterberg stretch frame and a refurbished Viking Voyager 17 inch. The Nolting company purchased Hinterberg and had a deal, might still be going on, for the combo for $4000.00. I was like you and had a small budget and didn't want to finance. What I wanted was the Babyloc Pearl with the Crown Jewel. However the $18,000.00 price tag on that combo with the computerized stitching system was more than I paid for my car and just couldn't justify it. I did compromise a bit but at this price point I could play around with it and see what features are a true *must* when I upgrade.
What I like about the Hinterberg is that I can make the poles any size I want.. right now I only have room for a queen sized but when I'm ready to expand my sewing studio I can always purchase new poles at any size. However, I find the wooden frame is harder to raise and lower the quilt as the metal frames were that I had researched. Also, the refurbished machine is old and heavy (at almost 80 pounds). The newer ones are lighter. You sound like you have a large area to keep it.. I put my frame up when I gather a hand full of quilt tops and then take it down so that I can put up my cutting and ironing tables. So I need help lifting the machine when I need to take it down. The wooden frame also tends to bounce a bit so following templates is a bit more difficult.
Overall I like the set up but would much prefer the Babyloc that I had played with at the quilting store...
Good luck in your search!
Kim