Generally the digital subtitles provided by the satellite receiver are pretty quick and very customizable.
Make sure you are using the DishNetwork Tuner/DVR for your captions, if your TV is trying to do the captions turn them off.
If you refer to the closed caption/descriptive video sections of the user guide for your tuner/dvr, you should find a whole lot of options. I am not sure which dvr you have but here is a link to DishNetwork manuals...http://www.dishnetwork.com/support/documents/receivers/default.aspx
Hope this helps Chuck