I feel your pain! There are some 4:3 laserdiscs of Babylon 5, so you might try tracking down those.
A blu-ray release is probably out of the question because of the way the effects were done, but I’d pay for the series again if they released an improved set on DVD. The existing NTSC DVDs are a bit better in terms of quality than the PAL, as I’m sure you know, but they’re 16:9 too. This site is informative if anyone is interested in this.