I too have researched this, and there are very few choices. The Samsung system is best used in a PAP mode, where both images take up equal screen real estate. But if it's PIP you're interested in, the only way I can see getting the best out of it would be to plug a satellite or cable box into the antenna jack and set the Samsung to channel 3 or 4, and then change channels at the box. Some cable companies pass HD channels down the pipe over the raw coax, so you could check that out as well.
I too have researched this, and there are very few choices. The Samsung system is best used in a PAP mode, where both images take up equal screen real estate. But if it's PIP you're interested in, the only way I can see getting the best out of it would be to plug a satellite or cable box into the antenna jack and set the Samsung to channel 3 or 4, and then change channels at the box. Some cable companies pass HD channels down the pipe over the raw coax, so you could check that out as well.