[Q] Questions about a Galaxy S4 Mini Clone?

Recently i bought a Galaxy S4 Mini clone (From China) off eBay and it's been doing pretty well, until recently. The phone has gotten progressively slower and can't handle many tasks at a single time, where as my old android phone (running 2.3 ) could handle multiple tasks at a time without even batting an eyelash. The current clone i have is running Android 4.2.2 and has exactly 1024 MB of Ram, and on average, due to background tasks (Rough 90 MB of ram) and what is allotted to run 4.2.2 (Roughly 0.98 GB of RAM) the phone only has about 25-30 MB of free RAM at any given time. I figure this might be what is causing the phone to slow down, and seemingly freeze on almost every task i give it, even when it is just one thing that is being done at a time. Now, Here are my questions, I saw an article on how android 4.4 can run well using only 512 MB of RAM, and was wondering if this update could be applied to my S4 Mini Clone since it has 1024 MB of RAM? Is this even doable? And if so, where could i search for a ROM or update to 4.4? If nothing can be done, or if my ideas won't work, i'm open to any suggestions and am willing to give any information that might be needed to help.

Also i was able to successfully root the phone using a guide i found here, if that is helpful in anyway.


System Information:

Model #: MTK6589
Android Version: 4.2.2
Baseband Version: MOLY.WR8.W1315.MD.WG.MP.V1.P2. 2013/07/16:44:44
Kernel Version: 3.4.5 lf@te-desktop#1 Thu Oct 24 15:48:45 CST 2013
Build #:MTK 6589
Custom Build Version: V001

System Information (From an app i found):

Brand: Alps
Model: MTK6589
Device: N/A
Product: hexing72_wet_lca
CPU: 4-CORE ARMv7 Processor rev 10 (v71)
CPU-ABI: areabi-v7a
RAM: 1024MB

OS:

VERSION: JDQ39
RELEASE: 4.2.2
KERNEL: 3.4.5
SDK: 17
FIRMWARE: eng.lf.1382600947