Default where to get exec 02 ROM?

Hello I had the rom orange spv m 5000, I changed to jasjar rom, but I am feelling that the operative system is still slow when you open a few application in the same time. and the tomtom is still slow.

so, the people say that the exec o2 rom is going faster so If any body can tell me where to get it, I will apreciate.thanks a lot.