Shortening the Mugen 2 and temp issues

[Moepus]

I assembled my system yesterday and I noticed that the heatsink is about 2 cm too tall, which keeps me from closing my case. Is there any way to take off the silver things on top and maybe a layer or two of aluminium plates, preferably without a saw?
If it isn't possible, what would be a good replacement fan? I'm looking for comparable cooling power, silence, and it should be shorter.
Also, I'm having some issues with temperatures. In idle, the cores are around 45+ (measured with core temp) and for some reason the fan isn't spinning at all. but perhaps I also used too much of the included thermal-grease (I pretty much emptied the entire pouch on to the processor).
Thanks for help in advance!

system info:
Intel Core i7 920
Gigabyte EX58 UD3R
Silverstone LC20 case

[StaticPressure]

Scythe S-Flexes are excellent fans

If you mean a comparable heatsink...well I'm not sure if I'm allowed to make suggestions here

[omniscienc3]

You used way too much thermal paste.

I read it should be something like the volume of two apple seeds.

Anyone correct me on this?