Planning PVE/CEPH cluster - recommendation

Hi all,

I am planning new HA Proxmox/Ceph cluster ( on Supermicro HW)
Can anybody see this setup and tell me if there will be any performance problem?

2x CEPH only nodes:
1xCPU Xeon 2603v3 1.6 GHz
32GB RAM
2x10GB for storage network
2x1GB for LAN
This nodes will be used only for CEPH

1x combined CEPH/Proxmox VM node
2x CPU Xeon 2620v3 2.4GHZ
64GB RAM
2x10GB for storage network
2x1GB fot LAN

HDD: In all nodes I am planning 3 (or 4) x 600GB 10k SAS and 1xIntel 3610 SSD for journal

On combined node will run only any little VM (2-4GB RAM, 1-2 vCPU)

I can add another node, no CEPH, no HDD(OSD), 2x 10GBit for storage network, only for running big VMs (2 - 3 VMs - jBOSS, Pentaho, Zimbra...)

For better performance I can add 2 x 400GB SSD to all CEPH nodes as another storage pool and use it for this "big" VMs

All OSD will be connected to HBA, journal SSD to onboard SATA.

My question:
1. For HDD pool - is using 10k SAS ok? or 7k wil be sufficient ? Will be there noticeable performance difference?
2. Both HDD and SSD pool on one CEPH cluster? is this possible?
3. HBA controller - AOC-S3008L-L8e(3008) SAS3HBA (ITmode) or AOC-S3008L-L8I(3008) SAS3HBA (IRmode) ? What will be better?

Thanks.
(and sorry for my English... :-))