This was discussed so often in the old forum, however let m give it another shot.
You can try to find a Detoma X501, a 3rd part surround amp that support powelring and B&O speaker.
There is also the option of getting an old, used beosystem 1 or 2, however that may not work together with the TV.
Lastly, if you shop around for surround amps, some support an adjustabkle line out which you can conect to the beolab speakers. However depending on speaker you may need to supply a 5 volt power to switch the speaker on (and have them stay on). For those with line in, you should be fine.
Personally I would recommend saving up for a B&O TV. To buy actually a full surround setup of beolab speaker is quite an investment, so why fiddle around and skimp on the surround amp?
JK
BS9000, BS2300, BC2, BL2500, BL3, Bl2, BS1, BV8, BC4, A8