Picking a UPS - really depends on what / how you need it to perform, how many devices you need to connect to it and what price point fits within your budget.
My main advice is to get one that protects against brownouts (low power) as well as surge protection. I have experienced power supply failure of equipment due to low power being supplied to my house (that particular problem has been since resolved by the utitlty company).
Check out
newegg, read reviews, and find one that satisfies your particular needs and budget.
Since I am new to the Mac world, I am not aware of which, if any brand has software available for the Mac. Of course, the software is not really required to provide the protection, mainly only provides extra feature sets such as saving open documents (for some software) prior to it shutting down. To me this is only handy if you are in the practice of starting documents and not saving them prior to leaving the house.