I can tell you right now, regardless of what you thought of the Samsung HTIB, the KEF speakers will be MUCH better. It shouldn't even be close.
If the 505 has the connectivity you require, it should do you just fine. Pioneer has some good models in that price range too (817/917). Also, if you like Harman Kardon their bottom of the line AVR 147 is around the same price as the 505. Don't underestimate HK's power ratings - their receivers are more than capable of producing clean powerful sound, especially for a bedroom. If you really want a great deal, look on HK or Onkyo's websites for refurbs. Good luck.