You definately need an expert to setup DR between the servers/sites.

You can have 2-node cluster (Standard edition of sql server supports) at both the sites and they can be mirrored.

Google about how cluster works. The data is stored on a shared storage so if storage fails, you entire cluster will be down.

If you are going to use 2012, you can configure AlwaysON but you'll need enterprise edition for that.