I think HAL9000 means RAC with TAF (Transparent Application Failover) using the preconnect option.
RAC requires two or more nodes with Oracle installed, plus the data is stored on a shared storage device, normally some sort of storage array external to the Oracle servers.
It really sounds to me like you do want a RAC solution. Keep in mind that RAC however is only HA if the hardware itself is set up properly. The key item that many sites forget is the storage, that is RAC and RAID is not sufficient, the site needs to have full replication of some sort in case the storage array itself suffers some sort of catastrophe.
So, in this case not only do you need two nodes (or however many is appropriate), but you also need to duplicate your storage subsystem in case the primary is lost. If you have two physical locations, the logical solution would be to configure one for the primary storage, and replicate the drive to the other site as backup.
Below is a link to some good information about the relative prices of various Oracle availability methods.http://www.dba-oracle.com/oracle_tips_failover_prices.htm