Hi. I'm currently on vacation until August. I live in Sweden but I have the capability to capture pal and ntsc laserdiscs at the moment. I'm not sure just yet about how to capture closed captioning but with Happy³'s ld-decode software I have full access to the vbi which is where that information is stored. I believe I have found some software that can extract closed captions from the vbi into an srt file but I have yet to test it. I'll be back from vacation around August and can try it then.
I'd be willing to capture some discs for special reasons such as it's not available or there's something super special about the laserdisc. I have to say that my priority at this time is to preserve all of the Star Wars laserdiscs first though.