SLK-900u with Vantec Tornado Fan.. is installation Hard?

[Audioaficionado]

can somebody explain exactly how to LAP the heatsink so when I get it today I know what to do?

does the heatsink come with fine grit wet/dry sandpaper or do I need to buy some? anybody recommend to me what type of sandpaper and grit size to get and from where?

All you have to do is check the cooling sticky 'Cooling-The Definitive Guide'

 

[Audioaficionado]

I don't believe they would do it on purpose, why do part (most?) of the heatsinks have a good finished base?

You're free to believe whatever you want, but machining ridges are not that uncommon on CPU heatsinks when you first get them.