I'll chime in since I also have a 58B860 (now in the bedroom). I also own a Samsung D8000 plasma, and now a Panasonic VT60 plasma.
All of the sets that you listed will give arguably better picture quality than the B860 in terms of black level and contrast. The B860 is still a fantastic set, but plasmas have gotten incrementally better year after year. My D8000 plasma is quite a step up from the B860 in terms of picture quality, and now my VT60 has taken it to a whole new level. The Samsungs you listed (F5300/F5500) will probably be closest to the B860 in terms of the overall 'look' of the image, but should be substantially better (black level, colors, contrast, etc.). However, the Panasonic ST60 is the current price-performance king, and has received great reviews. I would probably stay away from the S60 since it does not have an anti-reflective filter, and you might find it to be more reflective than your B860. I'd suggest checking out the ST60 and the Samsung models at your local video store, and go from there.
Room1:Panasonic 65VT60/Yamaha A1010/Denon DBT1713/Definitive BP8, CLR2300, SM350/Martin Logan Dynamo1000
Room2:Samsung 64D8000/Yamaha A730/Definitive BP8040, BP6, Mythos 3/PS3, Xbox 360
Office:Audioengine N22/Fiio D3 DAC/Athena P5/Polk PSW10
Car:Acura ELS DVD-audio/Focal