Synching Users across 2 WP Multi Networks on 2 separate WP installs

I have 2 questions;
1) what plugin do you use for this 'ask a question' and its relatetd Q&A forum? I like the way it works - or some plugin/forum similar?

2) I have 2 WP installs on 2 different domains both running Multisite and WP Multi Network. So far I created 2 networks A and B - 1 on each WP install (I separated the 2 networks on the 2 WP installs for the sake of not having all my sites down if something goes wrong).

Now say I want to sync the members of Network A on WP install 1 with those of Network B on WP install 2 - can I use User Sync, by making network 1 master and network 2 slave - i.e will this plugin treat the 2 Multi Networks on different WP install as single installs?

If not - how would I synch user accounts on 2 networks on 2 separate WP installs?

Sounds nuts I know - sorry!:slight_smile: