1)Fast internet connection. This is of paramount importance. Your machine(s) should be directly connected, not using WiFi, if at all possible. 2)Have both a laptop and a desktop. Use the desktop for most work, shadow copy everything to laptop for client site visits. 3)Invest in a hosting service like Dreamhost. Use svn there and host your webpage there and anything else you might be tempted to host at home. I even run bugzilla there (god help me). 4)Subscribe to cloud backup. Your choice, I like BackBlaze. Here, be selective about what goes to the cloud to avoid excess traffic. 5)Subscribe to DropBox, and use it for file exchange with your clients if at all possible, and as a synchronization mechanism with your machines. I use this to automatically back up all my accounting files between machines. 6)Set up your router to report log statistics weekly or monthly to try to ensure you are not being hacked. 7)Do not implement traffic controls on your router unless you absolutely must. See (1) above. 8)Do not self-host anything i.e. www, ftp, etc. Nice to play with but do you really need somebody wandering around on your machines? 9)Write all this stuff down somewhere and tell somebody where it is. I print out all my internet configuration stuff periodically and give it to my wife and kids, as well as all my accounts and passwords. You never know. 10)Somebody mentioned anti-virus. Yes, please and something credible. Many organizations you might work for may audit your machine for adequate AV or may require you to sign a binding statement of compliance. 11)Invest in something like VmWare Workstation or equivalent. This permits you to pretend to be any sort of host or database server that you need to be for a client. Otherwise, switching project server configurations is beyond painful. 12)I don't know about the UPS thing. Wiser minds than mine have already commented. My fear would be buying something pitiful that won't do the job, or worse, buying something that proves to need a new battery too soon, leaving me to figure out how to dispose of the battery. Seems like other investments might be more critical.
Allen