Good question Andy,

Googling   vara  qso ,  did bring  back a  few  hits , one is a  winlk    p2p  net , not really a qso  as  such , there is a  IO vara  group  with  ~ 500 members ,  posting there might  help , look to  be  mostly  usa based .. personally , I would suggest, vara-hf with  chat module  provides  a  near  replication of the  days  of  amtor , but, with considerable gain in s/n ,the other being the  link remains in duplex , rather like packet , there is no  master/slave .. also the  link only sends data , when  data is presented ..ie no data , it stop's when keying pauses ..little  unnerving at first ..

Used to  take 250  watts  to work  usa east coast on 7 with  amtor , probably now 25w  would suffice , though  on link round test using the east coast  Main kiwi web sdr , 5 watts has supported similar s/n mfsk link

CQ/QSO  - sometimes the  translation is a  little askue , the  comparison is  pre coded  messages ,  triggered by  multiple pass , minimal  'on air'  content , to actually  transporting the  full  message  content ..in live text  , the system is most suited and  robust , having  spent  hours in qso  on 10 MHz  during  testing , a most  unstable  band 

73 -Graham
g0nbd