Sonys range this year has some cracking LED's. If you would consider a 50" then the w829 is fantastic. Has 800hz refresh rate or thereabouts, also active 3d, but I bought mine for the refresh rate primarily. There is a 42 inch version also.
Re the UltraHD/SuperHd screens, is it true the sharpness of the maximum definition is dependent on the type of signal strength the service provider sends?