Buying a laptop processor?

Well my laptop overheated and burned out the processor and GPU. Well i have seen a new motherboard which comes with the GPU soldered on so theres really only one type that i can buy, but with a processor theres quite a lot of variety. All i know is that i have to look for something that is an S1, as thats the one that the fits on the motherboard. I have seen a processor it's an AMD turion II dual core 2.3 ghz It costs �36 and i have seen another which is for �16 it's an AMD 64 Turion 2.0Ghz MK-36 is the 0.3 ghz extra worth it for �20 I have also noticed that the turion processor says it has a DDR2 SDRAM controller (the other one doesn't specify this) is this going to be a problem because my laptop has DDR3 Ram