Stereo Receiver Recommendation Portable XM And/or Sirius Receiver Recommendation?

Portable XM and/or Sirius receiver recommendation? - stereo receiver recommendation

Hello, I'm looking to buy a Sirius and / or XM receiver, small enough that I wear when I'm able. Several questions:

1. You can get reception inside buildings with XM / Sirius?
2. is a portable device, a regular communication via the stereo Aux input?
3. These FM receivers generally get, normally?
4. Can you recommend in particular unit?

Thank you!