I have a Sony Walkman NWZ-A729 and I am stuck between 3 speaker docks the SRS-U10 (cheapest), SRS-NWGM30 (best reviewed) and the SRS-BT100 (biggest sound). I want the one that's going to be best in the long run. I like the sound of the SRS-BT100 but worried it won't take a non bluetooth device. Any help would be appreciated.