Configuration for a two machine ESXi cluster using VSA to present local storage to VMs
Solution 1:
This looks like perfectly reasonable design to me. I assume you want to place your virtual machines on data stores on VSA-based HP LeftHand Storage. You have the hardware and networking part covered: using two NICs on vSwitches for your HP LeftHand VSA, the ESXi's iSCSI VMkernels and possibly guests which access the HP LeftHand cluster is best practice; I suggest you create resource group reservations for the VSAs according to the user manual.
[Edit]Because just saw this in the comments to the original question: It is best practice to presented RAID-ed storage to the VSA which is made then virtualizied and made available in the HP LeftHand Cluster. The RAID level is depended on your requirements for capacity, performance and protection. RAID 10 is the way to go for you then.[/Edit]
One thing you need to be careful about is where you place your managers in this HP LeftHand setup. This is very important in a configuration with only two storage nodes! Right now I do not see a HP LeftHand Failover Manager (definitely the preferred option) in your design to maintain quorum in the storage cluster; or are you planning use the Virtual Manager? Depending on the uplink to your main data center (latency <= 20ms, bandwidth ~100Mbit/s), you might be able to place it in there.
PS: You might also want to make use of Remote Copy to replicate your VMs and data into your main data center; you already have everything which is needed in place to make it work.