SSG-140-SB and SSG-140-SH Cluster Compatibility

Hi there

I'm hopeing someone might be able to advise.

I have a SSG-140-SB that I want to set up in a cluster with another SSG-140 that I an waiting to recieve in the mail. I do not know if the SSG140 I an waiting to recieve is an SSG-140-SB (256MB memory) or an SSG-140-SH (512MB memory). If it was the latter would a SSG-140-SB and SSG-140-SH work as a cluster in HA mode?

I would really appreciate some input if anyone could advise.

Many thanks in advance.

Kevin