CX4-120 LUN Sizing for Exchange VM's

We have EMC CX4-120 Storage and 2 vSphere 4.1 Hosts, i am planning 5 VM's in this 2 hosts all are vmdk's no RDM, no Replication.

Configuration of the VM's

1. Win2k8 r2_x64_std /Exchange 2010 Std 4 VCPU's 8GB RAM, OS Disk 50GB, DB 75GB,

2. Win2k8 r2_x64_std /Exchange 2010 Std 4 VCPU's 8GB RAM, OS Disk 50GB, DB 75GB,

3. Win2k8 r2_x64_std /Exchange 2010 Std 4 VCPU's 8GB RAM, OS Disk 50GB, DB 75GB,

4. Win2k8 r2_x64_std /Exchange 2010 Ent 4 VCPU's 8GB RAM, OS Disk 50GB, DB 100GB, Log 100 GB,

5. Win2k8 r2_x64_std /Exchange 2010 Ent 4 VCPU's 8GB RAM, OS Disk 50GB, DB 100GB, Log 100 GB

in the storage i want to create 3 Different LUN's

1. OS LUN (Raid5) 5 x 50 =250 GB

2. DB LUN (Raid1+0) 3 x 75 =225 GB, 2 x 100 = 200 Total 425 GB

3. Log LUN (Raid1+0) 2 x 100 = 200 GB

Now Suggest me how much LUN Size i need to create for above requirement and suggest me best practices from Storage point of view and vSphere.

Thanks

VijayRaj