What HD Set-top boxes are available?

I've had the same Explorer 4240HDC box for years.  It works ok but I am rather tired of having a nasty standard def 4:3 guide on my high end HDTV.  It's ugly.  Are there other boxes I could ask COX to provide me that perform better and are geared towards HD widescreen 16:9 TV's?  I do not need nor want to pay for any DVR features however. Thanks for any tips.