maybe buy a half decent 5.1 amp for around £100 then club together your own speakers from old hi-fi stock. (??)
but yeah for a hundred quid, with amp inc. yor less than likely to get anything but 5 shitty pinny tinny speakers.
or alternatively but 1 speaker then walk around it 5.1 times. yes.
im callin it "active surround", keeps you on yer toes.