I dont think you need to run SSD's in RAID 0 (stripes)
It would not be significantly faster than having 2 SSDs as two disks C: & D:
If you do not have access to the server how are you going to boot off a DVD or USB to re install Windows
(after breaking RAID 1)
Or insert a spare hard drive, migrate partition to the new hard drive, make it boot device
then break RAID 1 and re set to two hard drives
then migrate back to SSD as boot drive
Some servers have management features & remote control way beyong ordinary PC's
(usually a special management card)
Is your Server a real server or a virtual server ? (have you actually seen it)
Are SSD's more reliable than hard drives ?
Yes in laptops where vibration & shock are likely to occur in use
are the SSD's server grade or retail PC grade ?
(1 out of 5 SSD's I purchased over the few years was DOA)
I think you should talk to the people who manage the server for specific advice before changing anything.
If you need more space consider adding a high speed server grade spinning hard disk
(10k rpm ?)
Finally the pair of disks can not be partly striped and partly mirrored (one or the other or a pair of disks)