Overscan problem

I have an anime hardsubbed divx movie that I’ve been trying to convert to DVD (in PAL format).

It turns out there’s a TV overscan problem and the subtitles are being cut off. I read that a solution would be to resize and have borders around it. Some of the suggested software to assisted with it were avisynth, fit2cd and tmpgenc but being a newbie, I’m finding it very difficult to understand it all.

I’m intending on using tmpgenc to encode the video with the Center (custom resolution) option but I’m not sure what it should be resized to. The video size is 720x400. Could anyone tell me the correct resolution that I should enter? And are there any other settings I should be aware of?

Or if anyone could suggest alternative methods for fixing the overscan problem, I’d greatly appreciate it.