The NILES TVA-20 works quite well. The other missing piece is a speaker level to line level adapter. We have had a hard time finding small sets with the appropriate hookups too.

If you carefully take apart the set and wire in the speaker level side to the wires going to the wimpy internal speakers, you will have a line level with RCA connectors on the other side. Of course you may void the warranty, so check out all the functions on the TV before you start and be careful. This is what custom installers are paid the 'Big Bucks' for.

We have done this many times without any problems. Be sure to take the time to adjust the TVA-20 for proper level, balance, and delay time. If you have a composite video output (probably not) use it to trigger the TVA-20 rather than the line level. It would provide a reliable trigger that will not need the level adjusted.