Hi,
These are very different products. Beosystem 3 gives surround sound and picture processing, but with the TV picture limited to 1080p (Full HD). Connection Hub (also known as the S8 Hub) is a stereo audio processor that does not do any picture processing, this only works with a TV that has an infra red remote control.
The choice is yours, I can help with cables once you have made your decision.
Kind regards, Steve.