Oracle setup required for heavy-ish load
Firstly, I will say that this workload is by no means heavy by Oracle standards; thousands of commits/sec are possible, easily. Secondly, however, what matters here is not your database and it's not your server: it's your storage. There are many options here; you won't go too wrong with something like NetApp (I don't work for them, just a satisfied user) and the question is, what size? Here ORION is your friend. Whatever storage array you choose, this will take care of your first level of resilience, if your first node fails you simply mount the disks on another and start back up again, and Oracle will perform crash recovery so no data will be lost.  

My advice is, get some numbers at a lower level - MB/s, IOPs - by performing a representative benchmark and take those to your nearest storage vendor and ask them what they've got. With NetApp at least, you can start fairly small and grow, adding another head for more resilience/better performance, adding shelves for more capacity, etc etc. Then test the crap out of it with Orion!