I had to deal with a similar problem myself having picked up a 61" rear projection TV for a case of beer...
I ended up going with this: http://www.amazon.ca/gp/product/B004F9XVBC/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1
The one big warning is that it will attempt to output the same resolution that you send it a signal in. This means that you need to be able to control your source's output resolution to match a resolution that your TV is capable of.
(ie, using an Ouya on a non-HD TV doesn't work using it. Using a HTPC does, because I can set the HTPC's output resolution to one that the TV will support).