The S-video/component connection for that TV sucks, IMO. I'm using the S-vid input for the on screen menu for my Proceed AVP, and that's it. Anything else plugged in here and the PQ is simply indecent.
Generally, BNC is considered a slightly better connection than RCA. Generally, too, unless your DVD player is manufactured by one of the higher-end boutique firms (in which case they sometimes include BNC outs), it will only come with RCA component outs, which seem to be a lot more popular a feature.
That said, I'd go with BNC, if possible, (and have). And assuming your DVD player is like mine, it will only have the RCA option; thus, to hookup, you can either run component video cables that have RCA's at both ends, and also get rat shack RCA--->BNC adapters ($5.00 per adapter) to hook up to the TV, or you can get component video cables that are RCA at one end (DVD) and BNC at the other(TV).
Whatever way you go, though, as between RCA and BNC, I doubt it will make that much difference in terms of PQ. So my answer is: either, or, with the nod to BNC if you can make it work.