any of the working breeds would suit you. although the different strains/lines. will differ within the seperate breeds. so once you choose what you want do your homework. find a decent working line and dont settle for less. one of the best crosses to me is patt/russell. 
 
  
I recon your right there "Cleanspade" this is the second litter of that cross I have bred and they have all turned out to be quality dogs. 
ATB