If you want to keep for phone stable to give it to your dad, then stick with stock or something like benzrom or dmod.
My personal suggestion is that you go for Maclaw's CM 10.2, which has the best battery life, an improved kernel and, well, it is android 4.3
If you wanted to try the latest features, but not final version yet, you could try Maclaw's CM 11. It's a great rom, that works flawless in our devices. Nevertheless, it stills has some small bugs that will be solved in future releases.
The link to maclaw is maclaw.p , give it a try!
PS: remember to flash gapps!