If I can find a very good anti aliasing filter that doesn't destroy too much detail, I will definitely use it. Have any of you got any suggestions?

With respect to the AR, the correct AR is obtained by upscaling pixel ratio 704x480 (640x480 = 4:3 AR) to 1280x960. The only way to achieve this is to crop the 8 outermost pixels of the GOUT (the overscan). Any other value will result in an incorrect AR. By removing the black bars you thus obtain a 704x274 source that will scale to 1280x548 for 720p.