It all depends on who is avaiable really, as you said with Bond in the side you can play a easierly play a 6-4 split. Looking at the top players in NZ:
J Marshall
H Marshall
S Fleming
N Astle
S Styris
L Vincent
B McCullum
J Oram
D Vettori
S Bond
J Franklin
C Martin
These are the players that i belive could probably get up to England and India in Test Cricket. Out of those 12 players the two worst IMO are Franklin and Martin so at full strength i would go for a 6-4 split. Even with Bond not in the side i would still go for a 6-4 split as a 5-5 split means you need to bring in an extra bowler. Tuffey might be best option but i don't think he is any better then any of the batsmen. 6-4 split is the way to go in IMO.
The big problem is opening the batting, do you keep Cumming, bring in How, throw McCullum up there, push one of the middle order batsmen up there or even put Vettori up there. The last one is the one i like