Thanks for the quick response,
I totally agree with your comments regarding backup - to elaborate a bit more on the setup, the primary site is basically a processing site, all exchange mail/accounting software is on a separate environment at the secondary site, the primary site in this case mainly has 2 servers - 1 is a glorified FTP server receiving files from clients - the 2nd is running specific software to process the files - once processing is done the requirement for the files is very minimal, we can easily get files resent by clients if needed. but we need the servers up.
In 10+ years(not with VMware) I have never had to restore a file 
- hope that doesn't bite me saying that! - I still need good backup to ensure the server config/applications safety though and will take your comments on board.
The main store for the VM's is shared storage (NFS share on NAS) and HA will be active as long as the NFS store is online, if we lose Host 1 - HA should auto boot the VM's on Host 2 and vice versa shouldn't it?
losing the NFS store would be a different matter, and I imagine a manual recover/boot of the replicated VM's off the localstore on the host - is that the case?
I guess a replication of the NFS store would be ideal.
Budget certainly can't stretch to a decent SAN unfortunately, have considered the VSA but kind of went off the idea, mainly due to requiring another windows server to run vCenter server as I believe you cant use the vCSA, which introduces more complexity and licensing costs as well as the increased cost of disks. Is that a fair assumption to make?
I should also mention both sites are only about 1km away from each other. so picking up the remote server and driving it to the primary site is an option if we lost the lot at the primary site.
I guess what I'm thinking is a solution that can be recovered no matter what within about 30mins - except for something taking out both sites completely, but I guess we'd have other issues to worry about then!
Hope that clarifies my thinking a bit - appreciate your time.