Contact them and contact other Internet providers in your area and see their plans about Business Class and see what Tiers they offer. It should cost you roughly about 20% more to get unlimited bandwidth and to have all ports open and possibly if your lucky you get static IP which is somewhat good.
I might kill someone to get business class for only 20% price increase. Where I am, consumer 25 Mbps is $55/mo; business 25 Mbps is $130/mo.
I manually back up all of my internals because those are more sensitive than my externals. My externals are only used for Anime purposes only which, ... I mean ... a total of 11TB+ (about 4TB of free space) of anime. So if I do a RAID on them I guess that could work too. I just don't understand the levels or numbers after the word RAID. Like RAID 0 or RAID 5.
Wikipedia is always a good place to start. The tldr is this:
RAID 1 - every disk is duplicated. 2 disks gives you 1 disk's worth of usable space.
RAID 5 - one disk used for recovery magic.
RAID 6 - two disks used for recovery magic.
It's worth noting that RAID (well, not RAID 0) provides
redundancy, which does not replace backups. Redundancy will only help if a disk dies - you'll need backups to deal with accidental deletion, file corruption (depending on the reason), malware, fire, theft, and a number of other things. If you're ok with that, you'll save money, but be aware of the risks.