you will need another heatsync. the cpu fan is moulded onto the cpu cooler. so you wont be able to just swap it out.
there are a lot of coolers out there that will do the job well enough. but selecting the rite fan can be tricky. i find the best thing to do is get a fan with a large rpm range. yate loon do 1 thats 900-2200rpm. which gives a huge range of potential. you can run it slow and have it whisper quiet or run it fast and get great cooling but often a lot of noise 2.
i have the fan thats on the front of that. they are whisper quiet infact there near silent. but they dont run particularly fast and only have mid range cfm (52) so temps are 5 degrees higher than with a 75cfm fan.