Just ti line up my solution for this:
1. SSO is way to costly to implement and to maintaine
2. The single password approach will give us fewer calls from all the systems we use- and a 24X7 support for users when they forget their password.
We will go with the solution from FastPassCorp thier FastPass Password Manager. They will implementent it in one day fixed price – Got 2 references that I called – looks promising.
I know you said you found SSO to be complicated but I think you will find it is the only way to get all of your applications and systems working together We use Impritiva Onesign and that works really well, no impact on the infrastructure and includes a self service module so your Helpdesk load will reduce anyway. It does work with AS400 (just checked that on the Website.)
SAP will integrate with AD for single sign on.