I think NCS still offers the service, I'm not sure how much tey charge though and I don't think you'd have any trouble finding someone on these forums or one of the better Dreamcast-specific forums that would do the job for you. The modchip only requires four solderpoints, so it's not very complicated to do. At least, i don't think it is, I haven't done one myself because I'm too cheap to pay for anything if the swapdiscs are free even though a modchip would be a lot nicer.
...word is bondage...