Which UPS to buy?

[bhushan2k]

System config:

Core i5 2400
Asus P8H61-M plus 2
FSP Saga II 500w PSU
500gb SATA 2 hdd
DVD RW
14" CRT monitor
No external gpu as using processor graphics

Just want 5 minutes backup to shut down the system..

 

[hitman4]

apc 600va for 2.4k

 

[d6bmg]

Want to add any GPU in future?
If no, then the UPS suggested in above post would be the best choice.