Hi Mike welcome to the communities,
vCenter Server is a must for HA and FT.
You should check out the vSphere Essentials Plus kit, which contains a vCenter license to manage up to 3 hosts and the ESXi licenses for 3 hosts with up to 2 processors each. This is should be the cheapest possibility for small environments like yours.
Nevertheless you need a shared storage to use those features.
It doesn't always has to be a SAN though. a NAS might do it as well. ESXi supports NFS shares as Datastores for VMs.
Vendors like Synology for example offer small VMware certified NAS boxes.
You can find VMware certified systems here: http://www.vmware.com/resources/compatibility/search.php?deviceCategory=san
Regards
Tim