With modern computers, software RAID usually is the better choice, often with software RAID performing better. Another advantage is that then you can move the RAID array from one computer to another without having to worry about on-disk format compatibilities. Unfortunately, IBM makes this difficult by often using LSI RAID HBAs which don't include the JOBD option. (At the lab where I work, we usually have to verify that the order has the right HBA part number so we get the JOBD option, although our salesman knows that now.)
RAID6 with a hot spare usually is the best choice for capacity (i.e. only 3 overhead disks) and it'll automatically start rebuilding on the spare when one of the active array disks fails.
Of course, whatever RAID choice you make, you should make sure you're using disks from different manufacturing batches. Too often, when using disks made in the same batch, when they have failures, several disks tend to fail very close together in time.
And do monitor the array health., of course. The extra reliability provided by RAID does no good if you don't notice that a disk has failed and don't replace it promptly.
Edited to add:
I'd suggest using the identical hardware configuration initially, if only so you can try to recover as much as you can from the damaged array(s). Then copy them to software RAID arrays.
Marantz SR7009/7.1.4/FH+TM/DefTech PM1000/LCR+TM amped