I tried lot of roms, but now i am using SlimKat 5.0 Stable Link here
, is the fastest kitkat rom i ever used.
Initially i face some issues at first in this rom, font & icon size are too small, then i download an dpi changer application and set to 233 (cappy's default resolution), then works perfectly.
* i use gapps (slim_minimal_gapps 4.4.2 which was lighter only 67 mb)
* i use Galaxy Laucher (downloaded from play store)
* Atrium for Facebook (alternative, because it takes too much ram)
* Pluma for Twitter (alternative)
* RAM 417 MB
Even using whatsapp, facebook & twitter, still i have 135 mb ram free.I highly recommend this rom, because it is fast, stable & better battery.