One last thing you may want to consider, but I'm not entirely sure will work, is a high end A/V receiver. I believe they are capable of taking in one video source and then converting them to another. I personally have never used one but they may do what you need. One that looks capable http://www.newegg.com/Product/Product.aspx?Item=N82E16882103262
. Just use the HDMI to DVI-D adapter on the HDMI output and it may work. Like I said my experience with these is limited and I would highly recommend consulting someone with more knowledge of receivers before trying anything.
After looking at the cost, you may be better off just getting an HDTV.