Xcp-ng raid storage question


I have acquired a Dell Equallogic PS6110 and it come with 10x 400GB SSD.
I am now trying to decide on the raid level (6,10 or 50).

Originally I tough that I would be setting the unit in raid 10 and get 2TB usable but this is not the case.
The EqualLogic is presenting 1.44TB usable.

I already have a couple of VM in my xcp-ng setup and it all total to 1.4 TB (thin provisioning) so I actually have about 600GB of real data in the VM.

At the moment I cannot buy more HDD so I am left with the option to choose another raid level (I will have an offsite backup on a very large SAN)

Could anyone please advise what raid level I should go for between raid6 and 50 to run VMs?
Most the VM run LAMP stack and a couple are for UNIFI, wikimedia etc… not big power hungry apps

Thank you all in advance