IPv6 Nat

I have two questions:

  1) Can you NAT between an IPv4 internal network and an IPv6 external 
network?

  2) Can you NAT between IPv6 networks.

Believe it or not, #2 is more important.  We need to make a lot of blades
look like a single machine (IP address).  Normally, a load balancer would
do this, which we are doing, but we need the outbound to look like a single
server too.

If the answer is yes to either of these, what version if IPfilter?

Thanks!
emike