Hi Zechs
1. Your current system is standalone SAP system? could you share the Database version?
2. In the new HA system you have to perform the SAP system copy along with Unicode conversion.
You have to export the source and import the same in target system. Single HA you can perform the multiple SAP SID's (SAP ECC & portal system) based on your hardware resources & sizing. its a very big task to switch the system to HA.IF possible you can get the SAP authorized consultant services.
3. Just follow the SAP System copy & New installation HA guide from the SAP link.
4. For system copy you have to use the SWPM in source & target systems. before starting in the production system. just do the test run in QAS or Dev system in HA environment along with unicode covertion
Regards
SS