So, my 18-year-old Kenmore KDC-215S stereo receiver/CD needs replacement. But there are many replacement options out there for a "dash" unit that will fit the existing frame. I don't need a lot, but Admirable and I have chatted about adding Sirius XM capability. I also notice some models with USB ports for uploading music files, etc. Bluetooth seems an important feature as well. Any pointers?