Can I check if I understand...you're asking if it's possible to have:
VMs on Fibre Channel attached LUNs in your primary site, replicated to your DR site, where they appear in NFS datastores
Is that right?
AFAIK This isn't possible today.
Using SnapMirror, when you replicate a volume containing a LUN, you get a volume containing a LUN at the DR site (and your virtual machine files are stored inside the LUN).
However, with NFS, virtual machine files are stored directly on the volume - there's no LUN involved.
I've heard of a few customers who use Fibre Channel in their primary site and iSCSI in their DR site - this might be a better option for you, and it shouldn't affect your budget too much, since it sounds like you're putting in an IP network for NFS in your DR site already?
This is pretty simple to setup - you just need to configure the iSCSI software initiator on the DR site ESX servers, and create initiator groups for your ESX server's iSCSI software initiators on the 2040 in your DR site.
SRM with the NetApp SRA will take care of mapping the replicated LUNs to the igroups when you perform a failover or test failover.
Hope this helps.
Thanks,
Luke.