The latest is the DDKQ8, you can give that try.
Btw which version are you using now??
If you really want speed, there are loads of custom roms made just for speed and performance, look them up.
Samsung GT-S5830 Galaxy Ace
ROM: AOKP 4.2.2
Scripts: CronMod INT2EXT4+
245MHz - 800MHz, SmartassH3