You are not limited to 352x240.
I will quote from the source you just used to say that you are.
Copied from
http://bmrc.berkeley.edu/frame/resea...g/mpegfaq.html
Can MPEG-1 encode higher sample rates than 352x240x30 ?
Yes. The MPEG-1 syntax permits sampling dimensions as high as 4095 x 4095 x 60 frames per second. The MPEG most people think of as "MPEG-1" is actually a kind of subset known as Constrained Parameters Bitstream (CPB).
I would suggest that you go buy Sorenson?s Codec package and see exactly what you can do with Mpeg-1. This post makes you look uneducated in the art of video encoding and is not good for your new business venture.