It's very clear that this is a mission-critical application need.
I recommend a clustered Oracle database with no less than four 8-core Wintel servers having at least 1 TB of RAM on each system along with 2 TB hard drives with a RAID 5 cluster and heartbeat connection between each pair of servers. Since we all know that California is a goner when the big one hits, you clearly need a RT (real-time, for you noobs!) connection with the same configuration located on the other side of the country. In fact, if you're a multi-national then its advisable to take a tax writeoff and host yet another same configuration in fscking Ireland too!
If that doesn't get you a renewable annual budget and a job-for-life then you need to become a manager and outsource the whole fscking thing to India where they'll do the work for minimum wage (what's that, $0.10/hour?) and you can manage it locally and report to the Board each year of all the hard work that you do.
Or just use a sqlite database with a small front-end configuration and Bob's your Uncle.