Mathieu Baudier wrote:
My question is whether it is worth using one of type A (with SSD drives) in order to host the critical data such as the web sites and the subversion repository (critical in the sense that these services should be fast, always available, and the related data as safe as possible).
Go with 10/15k RPM SAS, not Intel SSD or SATA if you want best availability. Intel SSDs have had firmware issues since they came out, I doubt we've seen the end of firmware changes on them.
If you want even higher availability go with a better provider, this is a good cloud hosting provider which uses VMware and high availability storage -
http://www.terremark.com/technology-platform/nap-data-centers.aspx
http://vcloudexpress.terremark.com/
Looks like they have 4 locations in Europe, I haven't used them myself but went through a presentation for them last year very impressive, though they are pricey. If you have simple requirements it's probably not bad though(will be a few times more $ than the hosting provider your looking at, but hey you wanted fast, always available, and safe, those aren't cheap). You can provision machines yourself, manage a remote firewall, and load balancers from their web UI.
nate