I'm a Sirius subscriber, I've got two Sirius tuners. One is an old model that is no longer for sale, the Brix Streamer, works fine for me. The other is the new S50. So I can't comment from experience about the radios that I'm going to recommend. The S50 is too buggy in my opinion to recommend as a gift unless your brother-in-law is tech savvy and doesn't mind a product that is ending its production run early...

The newer one is the S50 portable unit. Now when Sirius says it is portable, that means the the unit will playback stored Sirius content, MP3, and WMA files, but NOT LIVE reception. For that you will need XM or wait unitl later this summer/fall when Sirius releases a "true" portable. The S50 has been slightly unstable, although a new firmware has patched most of the problems with the unit. For more on this take a look at the S50 fourm over at Siriusbackstage.com. That's a great site for anything Sirius related.

If your brother-in-law needs a boombox type of setup I think the best bet would be the Sportster Replay or its twin the Brix Streamer Replay. You will need to order the boombox seprately from the tuner itself.

If he just wants to listen at home and in the car then the Starmate Replay might be the better bet. It has "Artist Seek" which will alert you when artists that you have marked are playing on another channel in addition to the "Song Seek" featured on the Sportster. You get up to 30 artists and songs to "mark". It also has a boom box, that just went on sale a day or two ago, but from the looks of it might be more fragile. At least the cradle that holds the tuner in place. I've haven't yet heard much about this new boombox.

Both of these have seprate "home kits" that supply an indoor/outdoor antenna plus cradle and power supply. You can then run "supplied" RCA cables to your home stereo. I've got a boombox for my Streamer and use it as a bedside alarm clock.

The links for the radios above will take you to "The Sirius Store" I've got no connection to them other than a happy customer. They are not related to Sirius Satellite Radio, they have their own on-line store.

I hope that helps!