Datastore / Disk setup for vSphere 5.5 initial host

I am about to setup a HP DL380 G7 server with 8 x 1.2TB disks with RAID 6, allowing approx.. 6TB usable local attached storage. I have 2 other like-for-like servers currently in use for Exchange/ Hyper-V. The plan is to eventually buy a SAN and move away from local storage, virtualise exchange (new server and migrate mailboxes) and convert hyper-v guests to VMware guests offline – and reuse the existing kit. I have 2 physical file servers that I’d like to consolidate as a new vguest on the host – approx. data required will be 4TB for users to access.

The current physical file servers run on a HP DL180 G6, which I am planning to beef up and use for VEEAM and Symantec Backup Exec (if they are able to co-exist) and a HP DL165 G7 which I am debating to reuse as a physical vCenter server (if the kit is good enough) or to virtualise as a guest system on the initial host.

My question is – How should I set up the disks? Am I able/should I consider a single datastore of approx. 6TB, which I can then split with separate vdisks as required for each guest? Or should I create separate datastores with one specifically for the file server data – if this will help migrate over to a SAN later perhaps? Am I right in thinking there is no longer a 2TB cap on datastores if I run version 5.5?

I have (vaguely) mapped out how I think the disks will be arranged on the datastore below - please can someone help and confirm if I'm on the right path here or suggest a better solution?

Thanks for your help in advance - it really is appreciated.